The stranger in the Seine A novel

Musso (The Secret Life of Writers) combines a baffling mystery with a memorable lead in this superior thriller. Roxane Montchrestien, longtime member of a French police brigade that hunts down the country's most wanted, attempts to resign after she gets caught up in a street protest that turns violent. Instead, she's transferred to the Bureau of Unconventional Affairs, an X-Files-esque division established "to investigate unusual cases that the judicial police couldn't find any rational explanations for." Soon afterward, a naked, amnesia-stricken woman is found in the Seine, and she asks for Roxane's predecessor before slipping away from the hospital where she's been recuperating. The plot thickens when Roxane learns that a DNA sample from the unidentified woman matches pianist Milena Bergman, who died a year earlier in a plane crash. Roxane teams up with Milena's fiancé to ferret out the truth, uncovering a web of deceit in the process. Musso delivers a satisfying resolution to the puzzle she constructs, and Roxane's inner conflicts about staying on the force in a time of social upheaval lend welcome emotional depth. Devotees of Christopher Fowler's Peculiar Crimes Unit series will be enthralled. (Aug.)