A good psychological thriller can be great entertainment, if the psychology is plausible. How does Dark Peak, by Adam J. Wright, stack up?

Mitch Walker is an English landscaper, a hard-working divorced father. Thirty years ago, his sister was abducted and murdered by a serial killer in Derbyshire, where his family lived at the time. His mother was so traumatized that she took him and fled away, and he never had contact with his father again.

Now he receives notice that his father has died, leaving him the Gothic-style mansion where they lived at the time, plus a fortune. Mitch doesn’t mind the money, but he doesn’t look forward to going back to the mansion. He still has nightmares about the place.

Elly Cooper is also divorced. She’s a former journalist who wrote a bestselling book about a serial killer and has been living off the royalties for some time. But book sales have fallen off, and her agent offers her a deal to do a new book, about a series of unsolved murders in Derbyshire, one of which is the murder of Mitch’s sister.

They will arrive around the same time, and their arrival will stir up old memories and old evil. It soon becomes apparent that the murders have not stopped – and someone in Mitch’s own family may be responsible.

The great weakness in Dark Peak was characterization – which ought to be the first thing you need to get right in a book of this type. If you don’t understand your own characters, how are we to believe you about psychopaths? The characters in Dark Peak commit the common fictional character error of keeping secrets from the police for reasons that advance the plot but seem unnatural in the real world. They also tell each other too much – real people rarely spill their guts to each other like these people do. It provides an excuse for information dumps, but again it rings hollow.

Also, for this reader, the murderer’s motivation, when finally revealed, didn’t seem very plausible.

The book is free for Kindle as of this review, so you might want to check it out, but I was rather disappointed. Cautions for disturbing content.