The Devil In Velvet by John Dickson Carr (1951)

Back in good King Charles's golden days, our hero now inhabits the much younger body of notorious rakehell Sir Nick Fenton—whose lovely wife will die unless history can be diverted. Complications include two other sexy women in the household. Fenton foils one clever arsenic plot, but is in more trouble than he knows.

The noises, smells, and violence of seventeenth-century London are splendidly if sometimes over-ostentatiously researched. Fenton, like Carr a fervent supporter of Charles II, gets entangled in copious politics, carousing, sex, and swordplay. There's a pitched battle in Pall Mall and a fraught audience with the King. Time is ticking away to the foreordained murder date.

Life as a rich nobleman is good, but Fenton's hopes of trading on knowledge of near-future history usually go astray. Also, though clues are scrupulously scattered, he has one huge blind spot when considering possible poisoners. A second, grimmer interview with the Father of Evil reduces him to despair.

The game isn't over, though, and there's time for some final swashbuckling on the battlements of the Tower of London itself before Fenton—though not in any way he'd expected—beats the devil and changes history after all. This full-blooded Restoration melodrama is great fun.

—David Langford