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Operation Sparrow: The Incredible True Story of the Spies Who Tricked Hitler and Won the War
March 16, 1944: Col. Florimond Duke, Lt. Guy Nunn, and Lt. Alfred Suarez embarked on the most dangerous mission of their military careers, Operation: SPARROW, a covert mission that would have them parachuting deep into Europe to negotiate Hungary's surrender to the Allies. As secret agents the men faced more danger than regular soldiers as combatants engaged in espionage are not granted prisoner-of-war status, allowing them to be treated as criminals; knowing full well the risks, the men are committed to serving their country and ending the war. Unfortunately, within three days they're imprisoned as Hitler sends in thousands of German forces.
Unbeknownst to their captors, the Sparrows' commanders have planned for this express outcome. While they're being shuttled back and forth between different custodians and countries, vehemently denying being spies and desperately holding on to the military uniforms that protect them under the Geneva convention, the agents execute their second underlying mission: in the fact of increasingly harrowing interrogation they take every opportunity to sow disinformation. In particular they claim that the Allies are planning an attack in the Balkans, miles away from the intended target of Normandy. They won't realize the full implications of their false intel until after the war.
While they never accomplished their original goal, Duke, Nunn, and Suarez waged their own war of deception, returning home from Europe as uncontested champions. Of the tens of millions of men who fought in WW2, these are the only three whose mission directly involved being captured and interrogated by the Nazis. Now, for the first time, historian Jason Bell brings this untold story to life.
Unbeknownst to their captors, the Sparrows' commanders have planned for this express outcome. While they're being shuttled back and forth between different custodians and countries, vehemently denying being spies and desperately holding on to the military uniforms that protect them under the Geneva convention, the agents execute their second underlying mission: in the fact of increasingly harrowing interrogation they take every opportunity to sow disinformation. In particular they claim that the Allies are planning an attack in the Balkans, miles away from the intended target of Normandy. They won't realize the full implications of their false intel until after the war.
While they never accomplished their original goal, Duke, Nunn, and Suarez waged their own war of deception, returning home from Europe as uncontested champions. Of the tens of millions of men who fought in WW2, these are the only three whose mission directly involved being captured and interrogated by the Nazis. Now, for the first time, historian Jason Bell brings this untold story to life.
288 pages, Hardcover
First published September 29, 2026
About the author
Jason Bell
2 books8 followersJASON BELL, PhD, writes narrative histories uncovering intelligence secrets of the Second World War. He is a professor of philosophy at the University of New Brunswick who has served as a Fulbright professor in Germany and taught at universities in Belgium, the United States and Canada. His first book, Cracking the Nazi Code, was a national bestseller.
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Displaying 1 - 13 of 13 reviews
Review of advance copy received from NetGalley
Spies, action, danger, heroes, and it's all true!
This was a riveting account of U.S. troops that went behind enemy lines during WW2, accomplished their task, and lived to tell the story.
The 3-person team called Operation Sparrow was led by Florimand Duke, an impressive Colonel who gave up his comfy existence to help the war effort. He parachuted into Hungary, along with Guy Nunn and Alfred Suarez, who each had a different talent that made the operation work.
Their aim was to get caught by the Hungarians and give over false info to convince the nazis that D-Day would happen on the Eastern Front. Not everything went as planned, as the group got tossed around from the Hungarian police to the Nazi military to the SS to the Gestapo. They endured hunger and squalid conditions and the possibility of murder every day. But they did what they were meant to do, and the nazis were convinced that keeping them alive would give them more intelligence.
The ending had me cheering as the group, housed in a prison in a castle, gets the head guard to surrender to the advancing US army.
A half-star off for being somewhat repetitive at times, and because the author seemed very sympathetic to the Hungarian government, claiming it wanted to protect the Jews, and well, I'm not confident it deserved it.
4.5/5
Thank you to NetGalley, Hanover Square Press, and Jason Bell for the opportunity to review an advanced copy.
This was a riveting account of U.S. troops that went behind enemy lines during WW2, accomplished their task, and lived to tell the story.
The 3-person team called Operation Sparrow was led by Florimand Duke, an impressive Colonel who gave up his comfy existence to help the war effort. He parachuted into Hungary, along with Guy Nunn and Alfred Suarez, who each had a different talent that made the operation work.
Their aim was to get caught by the Hungarians and give over false info to convince the nazis that D-Day would happen on the Eastern Front. Not everything went as planned, as the group got tossed around from the Hungarian police to the Nazi military to the SS to the Gestapo. They endured hunger and squalid conditions and the possibility of murder every day. But they did what they were meant to do, and the nazis were convinced that keeping them alive would give them more intelligence.
The ending had me cheering as the group, housed in a prison in a castle, gets the head guard to surrender to the advancing US army.
A half-star off for being somewhat repetitive at times, and because the author seemed very sympathetic to the Hungarian government, claiming it wanted to protect the Jews, and well, I'm not confident it deserved it.
4.5/5
Thank you to NetGalley, Hanover Square Press, and Jason Bell for the opportunity to review an advanced copy.
Review of advance copy received from NetGalley
Operation Sparrow: The Incredible True Story of the North American Spies Who Tricked Hitler and Won the War by Jason Bell Hanover Square Press (HarperCollins), September 29, 2026 ★★★★☆ (4/5)
I requested this advance copy because I enjoy reading about WWII history, and this was a story I knew absolutely nothing about. It turned out to be a fast-paced page turner.
On March 16, 1944, three OSS officers, Col. Florimond Duke, Maj. Alfred Suarez and Capt. Guy Nunn, parachuted into Hungary. On paper their job was to help negotiate Hungary's surrender and pull it away from Germany. That part fell apart almost immediately. Within days Hitler called in Hungary's regent, Admiral Horthy, German troops rolled in and occupied the country, and the three Americans ended up in German hands. But the surrender talks were never the whole story. Sparrow was one piece of Operation Bodyguard, the huge Allied deception plan meant to convince Hitler that the invasion he knew was coming would hit from the southeast, through the Balkans, and not at Normandy. The Sparrows were supposed to get captured, and then, stubbornly and under brutal persuasion, let that false story be dragged out of them.
Despite several hiccups, they pulled it off, in a masterful display of bravery. Over thirteen months they were moved through several prison camps, witnessed Nazi atrocities, and suffered through Gestapo and SS torture and interrogation, and they survived without ever revealing their true mission. They eventually landed at Colditz, the old castle POW camp, and the ending there is something else. As the war collapsed, the prisoners actually got the German officers and guards to surrender to them before the American troops even arrived.
Duke, a former Dartmouth football captain and New York Giants player who went into publishing at Time before the war, later told his own version in Name, Rank, and Serial Number (1969). But much of the operation was still classified then, and Duke had a habit of handing credit to others instead of taking what he deserved. He also left out entirely the story of Katalin Karády, the famous Hungarian actress who was arrested and tortured by the Gestapo for her part in the fight against the Nazis. Duke had written much of her story, but after visiting her in New York before publication, he came home and redlined all of it over the vehement objections of his publisher, because she was still active against the Soviet suppression of Hungary. Her story stayed out, but Bell tells it in full. He relies on Duke's book for many of the details but goes much further. He worked archives on three continents, consulted Hungarian histories, requested declassification of numerous documents, and traveled to Berlin, Vienna, Budapest and Croatia, where the Sparrows were held captive.
Bell is an interesting person to tell this story. He's a philosophy professor at the University of New Brunswick with a PhD from Vanderbilt and a stint as a Fulbright professor in Germany, and his previous book, Cracking the Nazi Code, grew out of his exclusive access to the classified papers of Canadian spy Winthrop Bell. He clearly has a knack for finding WWII espionage stories that slipped through the cracks.
This is a well-sourced deep dive into an important story that contributed to the success of the Normandy invasion, and one that is not well known. Three men went into Hungary with orders to get caught, and they kept their secret all the way to Colditz.
Thank you to NetGalley, Hanover Square Press/HarperCollins, and Jason Bell for an advance review copy in exchange for my honest review.
I requested this advance copy because I enjoy reading about WWII history, and this was a story I knew absolutely nothing about. It turned out to be a fast-paced page turner.
On March 16, 1944, three OSS officers, Col. Florimond Duke, Maj. Alfred Suarez and Capt. Guy Nunn, parachuted into Hungary. On paper their job was to help negotiate Hungary's surrender and pull it away from Germany. That part fell apart almost immediately. Within days Hitler called in Hungary's regent, Admiral Horthy, German troops rolled in and occupied the country, and the three Americans ended up in German hands. But the surrender talks were never the whole story. Sparrow was one piece of Operation Bodyguard, the huge Allied deception plan meant to convince Hitler that the invasion he knew was coming would hit from the southeast, through the Balkans, and not at Normandy. The Sparrows were supposed to get captured, and then, stubbornly and under brutal persuasion, let that false story be dragged out of them.
Despite several hiccups, they pulled it off, in a masterful display of bravery. Over thirteen months they were moved through several prison camps, witnessed Nazi atrocities, and suffered through Gestapo and SS torture and interrogation, and they survived without ever revealing their true mission. They eventually landed at Colditz, the old castle POW camp, and the ending there is something else. As the war collapsed, the prisoners actually got the German officers and guards to surrender to them before the American troops even arrived.
Duke, a former Dartmouth football captain and New York Giants player who went into publishing at Time before the war, later told his own version in Name, Rank, and Serial Number (1969). But much of the operation was still classified then, and Duke had a habit of handing credit to others instead of taking what he deserved. He also left out entirely the story of Katalin Karády, the famous Hungarian actress who was arrested and tortured by the Gestapo for her part in the fight against the Nazis. Duke had written much of her story, but after visiting her in New York before publication, he came home and redlined all of it over the vehement objections of his publisher, because she was still active against the Soviet suppression of Hungary. Her story stayed out, but Bell tells it in full. He relies on Duke's book for many of the details but goes much further. He worked archives on three continents, consulted Hungarian histories, requested declassification of numerous documents, and traveled to Berlin, Vienna, Budapest and Croatia, where the Sparrows were held captive.
Bell is an interesting person to tell this story. He's a philosophy professor at the University of New Brunswick with a PhD from Vanderbilt and a stint as a Fulbright professor in Germany, and his previous book, Cracking the Nazi Code, grew out of his exclusive access to the classified papers of Canadian spy Winthrop Bell. He clearly has a knack for finding WWII espionage stories that slipped through the cracks.
This is a well-sourced deep dive into an important story that contributed to the success of the Normandy invasion, and one that is not well known. Three men went into Hungary with orders to get caught, and they kept their secret all the way to Colditz.
Thank you to NetGalley, Hanover Square Press/HarperCollins, and Jason Bell for an advance review copy in exchange for my honest review.
Want to Read
October 3, 2026Interesting excerpt at LitHub:
https://lithub.com/on-the-secret-thre...
Sample:
"The plan was bold: parachute into enemy Hungary, surrender immediately, and claim they’d been trying to reach Yugoslav Partisans but had jumped in the wrong spot. Their “mistake” might make them prisoners of war with legal protections, rather than spies facing execution."
Sounds like quite a story. TBR
https://lithub.com/on-the-secret-thre...
Sample:
"The plan was bold: parachute into enemy Hungary, surrender immediately, and claim they’d been trying to reach Yugoslav Partisans but had jumped in the wrong spot. Their “mistake” might make them prisoners of war with legal protections, rather than spies facing execution."
Sounds like quite a story. TBR
Review of advance copy received from Publisher
THREE EXTRAORDINARY MEN
I like books based on true stories from WWII. The men and women who were alive during those days and fought for freedom truly were The Greatest Generation. Those who remained on the home front for whatever reason, whether it was age, health, sex, or whatever, for the most part did their best to support the war effort in the best ways possible. Then there were a few ordinary people, both men and women, who decided they would step up and do extraordinary things when all hell was breaking loose around them. Operation Sparrow is written about three such men who accepted a challenge that would have a major impact on D-Day. Without their daring exploit, D-Day would never have been a success. I highly recommend this book!!
On March 16, 1944, Col. Florimond Duke, the former New York Giants starter and more recently successful ad campaign man for his own major advertising company and wealthy tycoon, Capt. Guy Nunn, a multilingual propagandist, and Maj. Alfred Suarez, a radioman and explosives expert, embarked on the most dangerous mission of their military careers. It was known as Operation: SPARROW, a covert mission that would have them parachuting deep into Europe to negotiate Hungary's surrender to the Allies. That was the plan and it was a great plan, only it did not go as planned!
The three were quickly captured (part of the plan) but ended up as POWs of the Germans (definitely not part of the plan). They were supposed to “feed” intel to the Germans but were returned to the Hungarians and tried to flip them to join the Allies. They ended up being POWs for 13 months in a Gestapo camp, the last three in a commandeered castle. The three maintained their cover and never once cracked under intense pain and suffering during brutal interrogations. The three fed the Germans true intel that could be verified, but it was all OLD news and, therefore, not harmful to the plans for D-Day.
These three men and many others were finally rescued by brave young soldiers who had just come from liberating the few survivors of the horrors of the death camps. Those soldiers had walked past the ovens that were still radiating heat from horrific crimes! The smell had clung to them for days and would remain in their minds forever!
After returning home, Duke, Nunn, and Suarez all became successful businessmen. That is what made men like these three, The Greatest Generation. After surviving what they went through fighting for America’s freedom, they came home feeling invincible. They are the generation that made America Great. They were dedicated workers, devoted husbands and fathers, and helpers in their communities.
I was provided a complimentary copy of this book by Hanover Square Press and NetGalley. The opinions expressed here are entirely my own and without influence.
I like books based on true stories from WWII. The men and women who were alive during those days and fought for freedom truly were The Greatest Generation. Those who remained on the home front for whatever reason, whether it was age, health, sex, or whatever, for the most part did their best to support the war effort in the best ways possible. Then there were a few ordinary people, both men and women, who decided they would step up and do extraordinary things when all hell was breaking loose around them. Operation Sparrow is written about three such men who accepted a challenge that would have a major impact on D-Day. Without their daring exploit, D-Day would never have been a success. I highly recommend this book!!
On March 16, 1944, Col. Florimond Duke, the former New York Giants starter and more recently successful ad campaign man for his own major advertising company and wealthy tycoon, Capt. Guy Nunn, a multilingual propagandist, and Maj. Alfred Suarez, a radioman and explosives expert, embarked on the most dangerous mission of their military careers. It was known as Operation: SPARROW, a covert mission that would have them parachuting deep into Europe to negotiate Hungary's surrender to the Allies. That was the plan and it was a great plan, only it did not go as planned!
The three were quickly captured (part of the plan) but ended up as POWs of the Germans (definitely not part of the plan). They were supposed to “feed” intel to the Germans but were returned to the Hungarians and tried to flip them to join the Allies. They ended up being POWs for 13 months in a Gestapo camp, the last three in a commandeered castle. The three maintained their cover and never once cracked under intense pain and suffering during brutal interrogations. The three fed the Germans true intel that could be verified, but it was all OLD news and, therefore, not harmful to the plans for D-Day.
These three men and many others were finally rescued by brave young soldiers who had just come from liberating the few survivors of the horrors of the death camps. Those soldiers had walked past the ovens that were still radiating heat from horrific crimes! The smell had clung to them for days and would remain in their minds forever!
After returning home, Duke, Nunn, and Suarez all became successful businessmen. That is what made men like these three, The Greatest Generation. After surviving what they went through fighting for America’s freedom, they came home feeling invincible. They are the generation that made America Great. They were dedicated workers, devoted husbands and fathers, and helpers in their communities.
I was provided a complimentary copy of this book by Hanover Square Press and NetGalley. The opinions expressed here are entirely my own and without influence.
September 2, 2026
Thank you to Harlequin Trade Publishing and NetGalley for the advanced reader copy.
Operation Sparrow follows three American commandos who are tasked with parachuting into Hungary to meet with Hungarian leaders and help authorize their switch to the Allied side.
Initially, the mission appears to be a success. The commandos make contact with Hungarian leadership and are then supposed to be handed over to the German military for a brief interrogation before being returned to the Hungarians. From there, they would help orchestrate an underground resistance against the Nazis.
Unfortunately, the “Sparrows,” as the Americans became known, were betrayed and ultimately handed over to the Gestapo. What follows is their year-plus journey in German custody and their fight for survival, all while maintaining the secrecy surrounding the true reason they were in Hungary in the first place.
This book was very easy to read and moved at a great pace. Although it covers more than a year of events, it never gets bogged down with too many miscellaneous details, making the story easy to follow and keeping the focus on the experiences of the three men.
I would highly recommend Operation Sparrow to anyone interested in World War II history, especially readers who enjoy true stories about little-known missions and the incredible determination of those who lived through them.
Operation Sparrow follows three American commandos who are tasked with parachuting into Hungary to meet with Hungarian leaders and help authorize their switch to the Allied side.
Initially, the mission appears to be a success. The commandos make contact with Hungarian leadership and are then supposed to be handed over to the German military for a brief interrogation before being returned to the Hungarians. From there, they would help orchestrate an underground resistance against the Nazis.
Unfortunately, the “Sparrows,” as the Americans became known, were betrayed and ultimately handed over to the Gestapo. What follows is their year-plus journey in German custody and their fight for survival, all while maintaining the secrecy surrounding the true reason they were in Hungary in the first place.
This book was very easy to read and moved at a great pace. Although it covers more than a year of events, it never gets bogged down with too many miscellaneous details, making the story easy to follow and keeping the focus on the experiences of the three men.
I would highly recommend Operation Sparrow to anyone interested in World War II history, especially readers who enjoy true stories about little-known missions and the incredible determination of those who lived through them.
August 6, 2026
First of all, I’m incredibly grateful to HarperCollins for allowing me to read and review this book for free. I cannot believe this story is not more widely known and discussed.
I have been studying World War II for many years, and just when I think I’ve learned everything there is to know, another incredible story comes along that I had no idea existed. The brave individuals featured in this book were not seeking fame or fortune. They willingly put themselves in unimaginable danger, enduring horrific torture and countless hardships for a cause greater than themselves.
Their actions helped change the course of history and saved millions of lives, especially through their impact on the Normandy invasion. I’ve had the privilege of walking the beaches where the D-Day landings took place, and I wish I had known this story before visiting. Understanding the role these individuals played in deceiving the Nazis would have given me an even deeper appreciation for the sacrifices made there and how differently history might have unfolded without them.
This is an extraordinary story of courage, sacrifice, and determination. I hope more people read it, are inspired by these remarkable individuals, and help ensure that their bravery is never forgotten.
I have been studying World War II for many years, and just when I think I’ve learned everything there is to know, another incredible story comes along that I had no idea existed. The brave individuals featured in this book were not seeking fame or fortune. They willingly put themselves in unimaginable danger, enduring horrific torture and countless hardships for a cause greater than themselves.
Their actions helped change the course of history and saved millions of lives, especially through their impact on the Normandy invasion. I’ve had the privilege of walking the beaches where the D-Day landings took place, and I wish I had known this story before visiting. Understanding the role these individuals played in deceiving the Nazis would have given me an even deeper appreciation for the sacrifices made there and how differently history might have unfolded without them.
This is an extraordinary story of courage, sacrifice, and determination. I hope more people read it, are inspired by these remarkable individuals, and help ensure that their bravery is never forgotten.
Review of advance copy received from Netgalley
ARC provided by the publisher via NetGalley in exchange for an honest review.
As someone who reads a lot of non-fiction about the world wars I'm always looking to learn new things and expand my understanding of the conflicts so I was thrilled when I saw this book about WWII. Operation Sparrow was something that I had never heard about, but I was hoping it was in the same vein as Operation Mincemeat and I am happy to report that it was just as fascinating and harrowing to learn about.
I don't think there's an easy way to sum up the actual Operation Sparrow but what I can say is that it was really interesting to learn about the men that pulled it off and some of yhe key players that helped them and who also played their part as spies. It was stressful and heartbreaking and amazing and im delighted that I now know thus story.
I also loved the writing, there's a specific way of writing non-fiction that almost feels like fiction and this was exactly that. It was never dry or repetitive while still giving you all the facts to paint a vivid picture of the operation.
Overall this was a really well done book about a little know aspect of the war. I learned a lot and I'm glad I got to read it. Definitely recommend if the topic is something that interests you.
As someone who reads a lot of non-fiction about the world wars I'm always looking to learn new things and expand my understanding of the conflicts so I was thrilled when I saw this book about WWII. Operation Sparrow was something that I had never heard about, but I was hoping it was in the same vein as Operation Mincemeat and I am happy to report that it was just as fascinating and harrowing to learn about.
I don't think there's an easy way to sum up the actual Operation Sparrow but what I can say is that it was really interesting to learn about the men that pulled it off and some of yhe key players that helped them and who also played their part as spies. It was stressful and heartbreaking and amazing and im delighted that I now know thus story.
I also loved the writing, there's a specific way of writing non-fiction that almost feels like fiction and this was exactly that. It was never dry or repetitive while still giving you all the facts to paint a vivid picture of the operation.
Overall this was a really well done book about a little know aspect of the war. I learned a lot and I'm glad I got to read it. Definitely recommend if the topic is something that interests you.
Review of advance copy received from NetGalley
⭐⭐⭐⭐⭐
Whew. The fact that this actually happened is what kept blowing my mind while reading. Operation Sparrow tells the true story of three Allied operatives sent behind enemy lines during World War II, and the twists, risks, and deception involved feel straight out of a spy novel.
Jason Bell brings these men and their mission to life in a way that is both gripping and incredibly human. I found myself constantly thinking, “There’s no way this is real,” only to remember that it was. Fascinating, tense, and packed with little-known history, this is the kind of nonfiction that reads effortlessly. A must-read for anyone who loves WWII history, espionage, or stories of extraordinary courage.
Whew. The fact that this actually happened is what kept blowing my mind while reading. Operation Sparrow tells the true story of three Allied operatives sent behind enemy lines during World War II, and the twists, risks, and deception involved feel straight out of a spy novel.
Jason Bell brings these men and their mission to life in a way that is both gripping and incredibly human. I found myself constantly thinking, “There’s no way this is real,” only to remember that it was. Fascinating, tense, and packed with little-known history, this is the kind of nonfiction that reads effortlessly. A must-read for anyone who loves WWII history, espionage, or stories of extraordinary courage.
Review of advance copy received from Publisher
I was fortunate enough to be provided an advance copy of Operation Sparrow by the author's publicist. I was not asked for a review, but here it is anyway! What a fantastic, harrowing read. I have covered the spy stories associated with Operation Fortitude in great deal in the past, but, as Jason Bell points out in his book, the 3 US commandos that dropped behind enemy lines into Hungary as part of the broader Allied deception campaign, is lesser known. Jason managed to tell the story's big picture while zooming in on the very human bravery and valour that makes this book so 'un-put-down-able'.
October 6, 2026
This book caught my attention quite quickly and read a lot like a thrilling spy novel rather than a historical account. I knew nothing about this mission that happened that helped the allies have a successful D Day landing. Three men get dropped into Hungry behind enemy lines with the intention of getting caught in order to throw the Nazis off the trail of where D Day will actually happen. Three men with very different backgrounds and different skills who can together cause chaos from inside. Very well researched and perfect for those who love war history.
Thank you to NetGalley and Hanover Square Press for the ARC of this book.
Thank you to NetGalley and Hanover Square Press for the ARC of this book.
Review of advance copy received from NetGalley
Operation Sparrow
By Jason Bell
Pub Date: Sep 29 226
I am a huge gan of historical reads when tue content is war related. The things these men sid was incredible. The research that went into writing this book is fantastic. I thoroughly enjoyed the book and will keep an eye out for Jason Bell's future releases.
Thank you to NetGalley and Harlequin Trade Publishing for the opportunity to read this book early in return for my honest review.
By Jason Bell
Pub Date: Sep 29 226
I am a huge gan of historical reads when tue content is war related. The things these men sid was incredible. The research that went into writing this book is fantastic. I thoroughly enjoyed the book and will keep an eye out for Jason Bell's future releases.
Thank you to NetGalley and Harlequin Trade Publishing for the opportunity to read this book early in return for my honest review.
Review of advance copy received from Publisher
This is the amazing true story of three American commandos whose mission was... to get caught. It all comes down to setting up the Allies for success at D-Day and one of the tools was that of deception. The book reads like a novel but is a true story. The author draws on a number of intersecting stories and presents a picture of the last year and a half of the year that many people are completely unaware of.
Review of advance copy received from NetGalley
I received an advanced digital copy of this book from NetGalley in exchange for an honest and original review. All thoughts are my own.
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