Murder on the Left Bank

By Cara Black Soho Crime, 276 pp.

The loveliest part about a long series is that its characters drive the action, rather than the reverse. Cara Black’s 18th novel about Aimee Leduc — head of Leduc Detective, chic Parisian maman, cheerful foil to the uptight Inspector Melac — features one of her strongest mysteries, about a group of murderously corrupt cops chasing the document that will expose them. Aimee has promised her partner she’ll stick to cybersecurity (it’s 1999, and her clients are “nervous about possible Y2K malfunctions”), so naturally, she takes on the case, which proves full of dangerous surprises. But the real joy of “Murder on the Left Bank” is in its familiar cast and its thoughtful, witty, occasionally melancholy evocation of Paris, the city where we keep so many of our most beautiful ideas about what life might mean.

Charles Finch is author of the Charles Lenox mystery series, most recently, “The Woman in the Water.”