Philip MacDonald's story was one of the first Penguin editions published, and has been the basis for no fewer than six motion pictures: 1929's "Lost Patrol," John Ford's 1934 "The Lost Patrol," Russia's 1936 "The Thirteen," 1943's "Sahara, remade in 1995, and the 1953 western "Last of the Comanche." With all those versions floating about, it's not surprising if you find the tale familiar.
Ten soldiers, in the desert during WWI, bury their fallen commanding officer - who never shared their mission or orders. With limited supplies, their Sargeant opts to head for the nearest river, assuming their position on the map is accurate. In the process, he must avoid enemy Turks/Germans, undeclared but likely unfriendly native Arabs, and their own thirst. Fortunately they find a watering hole, much father away than it looked - but after one night, it's clear they are not the only ones gathered there.
Stranded, hunted by an unknown enemy, and increasingly short on supplies, the tension and strain bring out the worst in each man. Social preferences, religious prejudices, and fear of the unknown become magnified, and petty insults cause as much enmity as that felt towards the unknown snipers.
As in any troop, we get to know some of the characters very well - their interests, motivation for signing up to fight, and regrets - others are just shadows. Most interesting is the Sargeant, carrying the weight of command, schoolyard referee, and knowledge of their likely fate on his shoulders. But this is a military story, and your interest is caught up in the fate of the patrol, rather than the fate of the individuals.
It's an incredibly tense story, if you've never seen any of the movies. If you have, it's a quick read and differs in some way from each movie version. The story is, however, filled with the verbal slurs used during wartime towards those perceived to be the enemy or of lessor social standing, and the Jewish character is subject to antisemitic comments regrettably authentic to the time. And at least one of the characters regularly references the "Ten Little Indians" nursery rhyme (using an even more inappropriate title) - as that nursery rhyme concludes with each titular character having been done away with, the subject is somewhat apropos - just to add to the atmosphere and general stress. ("Patrol" was published over ten years before Agatha Christie's "Ten Little Indians" aka "And Then There Were None.")
Author Philip MacDonald served with the British cavalry in Mesopotamia during WWI, so he had firsthand knowledge of his subject. He later trained horses for the army, and was a show jumper, but ultimately he moved to Hollywood to write novels and screenplays (not for Patrol though), radio (and television) scripts,. He was one of the most popular mystery writers of the 1930s and wrote other genre under various pseudonyms.
I should also mention the 203-page Casemate edition has a helpful glossary in the back for such words as "gora," which I trotted mid-read to Google to decipher. I do wish they would footnote the definition, mention the glossary at the beginning, or put the list in the front of the book.