The Cornerstone: A Historical Conspiracy Thriller

by Josh Lowder

A homicide investigation turns into a desperate chase to uncover a secret dating back to the American Revolution that could alter the course of history.Detective Brian Howard thought he had just about seen it all in his years on the police force in small-town Brookhaven, Louisiana. But when a security guard is murdered at the local Reveldome Museum and nothing appears to have been stolen, Howard finds himself drawn into an intricate mystery that stretches far beyond that of his hometown. With the help of an unlikely source, he begins to uncover cryptic clues that will point him to secret societies, lost American history, and a conspiracy that could shake the very foundation of the United States. Haunted by his own family’s mysterious past, Howard discovers that solving this case may just provide closure to questions that have burdened him for years.

Racing against the clock, Detective Howard and his new partner will go from the humid streets of South Louisiana to the sacred halls of Washington, DC, finding themselves unwittingly in the shadowy crosshairs of a forgotten group determined to keep the past buried at any cost. Each revelation brings them closer to a truth that has been guarded for generations—a truth intertwined with a missing piece of American history—the lost United States Capitol cornerstone. With danger closing in, Howard is forced to confront his own past while risking it all to solve a mystery that will change history – and potentially his own future.

Blending police procedural, historical intrigue, and relentless suspense, The Cornerstone is a gripping thriller filled with secrets, sacrifices, and the enduring power of truth.

303 pages, Paperback

Published August 25, 2026

About the author

Josh Lowder is the author of the historical conspiracy thriller, The Cornerstone. As a former police officer and current fraud investigator in financial crimes, he blends his experience in criminal investigations and passion for history into crafting gripping, real-life narratives.

Follow him on:

Facebook - Josh Lowder, Author

Instagram - author_joshlowder

Website - www.officialjoshlowder.com

Reviews

[Kimberly]

If you’re looking for a thriller that grabs you by the throat and refuses to let go, this is it. From the very first pages, the story launches into a nonstop adrenaline rush packed with action, suspense, secrets, and twists that I absolutely did NOT see coming.

This book is smart, intense, cinematic, and incredibly hard to put down. If you love thrillers that keep you guessing until the very end, move this one to the top of your TBR. You won’t regret it.

[Steven Finkelstein]

This book focuses on Detective Brian Howard, who has worked for the Brookhaven Police Department in Louisiana for many years. He has plenty of experience and savvy, but when a security guard is found dead in a museum, the clues take him in increasingly more perilous directions. Could a centuries-old conspiracy really be behind the guard’s killing?

This novel somewhat resembles the National Treasure movies or one of Dan Brown’s stories. The author does an excellent job of mixing exciting scenes with historical information relevant to the plot. Howard is a capable protagonist, and as the reader is drawn further into his world, it becomes more difficult to put the book down.

[Peter Barrows]

I was excited for this book so I ordered a signed copy during prerelease. I’m so glad I did. I couldn’t put it down and finished it in two sittings.
Josh Lowder blends history and suspense like a true artist. The book is full of several twists that make it near impossible to find a good spot to put it down for the night.
Lovers of American history and anyone who enjoys a crime/mystery/thriller will enjoy this book. I found myself googling a lot of the historical references after I finished because I wanted to learn more. Highly recommend giving this novel a read.

[Shari Deruiter]

Best book I’ve read in a long time! Kept me at the edge of my seat! I couldn’t put it down!! I had to find out what happened next!! Twist and turns throughout. I know my heart rate went up a few times!!