Perhaps the only urge stronger than to write a diary of one's own is the compulsion to read someone else's. Anaïs Nin's fiction is nowhere near as widely read as the many volumes of her journals, while Anne Frank's Diary of a Young Girl is required reading in schools around the world. And Samuel Pepys, the 17th-century British civil servant, would most likely have sunk into complete obscurity if not for the lively reckoning he kept of the times he lived in, the people he knew, and what he thought about it all. Because of his diary, Pepys's life is an open book; but what of the myriad personalities he mentions in passing? In Jem (and Sam), Ferdinand Mount uses his putative ancestor Jeremiah Mount, a real-life drinking companion of the great diarist, as a springboard into the tumultuous 1600s.

The premise of Mount's novel is that "Jem" Mount was more than just a drinking buddy of Pepys's; indeed, he was something of a rival--albeit an unsuccessful one--in love, in politics, and ultimately in literature. The fictional diary begins with its narrator's childhood in Kent, and follows his progress: at 17 he's apprenticed to his uncle in Dover, and by 21 he's joined the civil service in Oliver Cromwell's new republic. Needless to say, Jem (who has already learned the fine art of cooking the books while working for his uncle) finds London a far more lucrative place to apply his skills, and at first he does well. It is during these heady, early days that Jem meets Sam Pepys, "a little man with eyes like children's marbles knocking together and a nose like a quill which he dipped into mine host's ink with a quick sucking motion as though he wished to empty the tavern before he was emptied out of it. He was all motion like a turbulent sea, yet neat." The two become friends, but when Cromwell dies and the monarchy is restored, Jem jumps from government employ into the service of a war hero whom he is secretly cuckolding, while Pepys stays in the civil service. It isn't long before Jem realizes his mistake, as he is gradually transformed into a glorified nanny, major domo, and occasional paramour while his friend rises spectacularly through the government ranks. Soon Jem is coveting everything Pepys has and doing his best (which of course, isn't enough) to get it all for himself.

Ferdinand Mount has crafted this picaresque tale with wit, intelligence, and a thorough knowledge of the times and the vocabulary with which to describe it. History real and imagined are seamlessly interwoven in a style Pepys himself would have been glad to own. By the end you'll find it difficult to believe the real Jeremiah Mount didn't write this diary; at the same time, you'll probably never look at Samuel Pepys's own effort in quite the same way again. --Alix Wilber