BLUE MONDAY. By Nicci French. Pamela Dorman Books/Viking. 322 pages. $26.95.

London psychotherapist Frieda Klein’s livelihood deals “with the mess and pain inside other people’s heads.” Her newest client, Alan Dekker, obsessed with having a child, seems no more troubled than other patients.

When the male child he describes suddenly turns up in the press as a kidnap victim, Klein grows alarmed. Is Dekker involved with his disappearance?

Fearing a crime has been committed, Klein brings her suspicions to Detective Chief Karlsson. The detective thinks he sees a connection between the present-day kidnapping and the abduction of a young girl 22 years earlier.

Suspense builds as Klein and Karlsson delve further into the twists and turns of the mystery. Scenes shift from Klein’s speculations to the terrorized child’s thoughts to the kidnapper’s schemes.

Klein, Karlsson and ancillary characters are realistic and credible. Believable dialogue and uncanny coincidences add to the novel’s flow. Klein is portrayed as a cynic and a loner, married to her work.

An insomniac, she eschews romance and family relationships and spends many sleepless nights roaming city streets deep in thought. But an unexpected romance threatens to end her equanimity and provides an undercurrent of personal confusion.

“Blue Monday” is an attention-holding psychological thriller with a surprising conclusion, and the first in a series of Frieda Klein mysteries to be penned by Nicci French, the pseudonym for the husband-and-wife writing team of Nicci Gerrard and Sean French.

After Monday, what does Tuesday hold for Klein?

Reviewer Rosemary Repeta, a writer based in Charleston