Man Overboard by Tim Binding

Deep-sea double agent

But it's not even that simple. This isn't the mindless patriotism practiced by some. For this kind of Englishman, it was "string and sealing wax and a regular tot of bloody-mindedness" which singled out the British war effort. Binding identifies exactly "what separates us from the Cowhands [Americans]. They do not understand the necessity of indifference."

And they don't come much more indifferent than Commander Crabb – the real-life hero of Binding's delightful, surprising, read-in-a-single-glorious-gulp new novel. A heavy-drinking, unemployable, near-feckless wastrel before the war, Lionel Crabb was transformed by service into a heavy-drinking, unemployable, near-feckless Able Seaman. Eventually commissioned into bomb disposal, he was posted to underwater disposal in Gibraltar with the words "Frankly, Crabb, we wouldn't mind you drowning."

But there in the Mediterranean, "opposed to any form of exercise", he found his unexpected metier – deep sea diving. Protecting British shipping from the Italians' constantly inventive limpet mines and two-man subs, he made a considerable name for himself. He ended the war a Commander and won the George Medal. But that's when his problems started.

He was now surplus to requirements – and clearly still a determinedly loose cannon. But rarely do narrators come this unreliable – and this is the joy of Binding's writing: he captures the soul of a man who knows he is constantly making a hash of things but can barely admit it to himself.

He undoubtedly had a serviceable skill and once the enemy shifted from Berlin to Moscow, it was in even greater demand. Through his ever unreliable eyes, we see him being manipulated by agents, double agents and moles. That is until he finds himself on the other side of the Iron Curtain. Because Binding's novel aims to unravel the mystery of Crabb's disappearance: Crabb finally went down and didn't come up in 1956. Binding paints a picture of Crabb, now dying, looking back on two careers, one for the Royal Navy, the other for the Soviet Navy.

And if, like me, you wonder how on earth a wool-dyed patriot like Crabb could calmly work for the Reds, Binding has a last twist in the tale which makes the entire story slot into place.