Andrew Rosenheim has chosen the relatively familiar territory of pre-war America for his ffth novel, a taut and believable political thriller set in late 1930s Washington.

Familiar it may be, yet it has at its heart a little-known conspiracy which might have changed the course of 20th-century history.

This is a traditional thriller, with all the requisite tensions and fast-moving plot. It is made fresh through meticulous historical detail, a new set of enemies in the German-American ‘Bund’ organisation who are ardently pro-Nazi, and by a cumulative and rather subtle appreciation of the character and motivations of its chief protagonist.

Jimmy Nessheim is a 26-year-old inexperienced Special Agent in the newly formed FBI. He’s secretly assigned by his maverick boss to infiltrate the Bund, where he is soon at the centre of a deadly plot — and in a lot of danger.

Despite their willingness to murder, it soon becomes clear that the Bund are merely bit players as Jimmy’s next undercover assignment takes him to the centre of Washington’s high society and he finds himself in a web of political intrigue, secret lives and at the edges of a far more sinister plot, guaranteed to keep Roosevelt from declaring war on Germany.

Rosenheim delivers a great deal of information in the punchy style of a classic literary thriller.

There are the depths of character in Jimmy that keep us rooting for him, the stress he carries due to faking his medical, his unease with lying to his family, the determination it takes to leave behind the town where he’s a local hero, and the loneliness that casual relationships cannot seem to banish.

Rosenheim, an Oxford author who came to England from America as a Rhodes Scholar in 1977, and previously worked for Oxford University Press, quit his job as managing director of Penguin Press to write full time. Judging by this book, he made the right choice.