Written by Tess Gerritsen — Over the course of 12 books, the partnership of Rizzoli and Isle has become as well-established as, say, Laurel and Hardy or Lennon and McCartney. Or maybe we can add Cagney and Lacey, because these two women are close friends as well as kickass work colleagues.

Boston homicide detective Jane Rizzoli has a husband and young child, while things are a lot more complicated for medical examiner Maura Isles, whose relationship with a local Catholic priest strays way beyond the platonic. But while their personal lives may be poles apart, when there two get together on a job they are a single-minded force to reckoned with.

The book opens at a funeral – one of several in a story littered with death. The faceless narrator is there, struggling with her emotions as an old schoolfriend is laid to rest. But this woman isn’t biting back the tears, she is trying her best to produce them, to fit in with the crowd and draw as little attention to herself as possible. It’s the first sign that Holly is not all she seems…

Meanwhile, Maura is also in emotional turmoil as she visits her mother in prison. How do you connect with a serial killer who is dying of cancer and still delights in pulling the strings on a daughter she gave up for an adoption as a baby? Isles is torn and vows never to return, but that’s a vow she’s made and broken before. She has to put personal issues aside when work calls. A director of independent horror movies has been found dead in her Boston apartment and the gruesome scene she has been found in would fit right into any of her films. Cassandra Coyle is lying in her own bed, her eyes removed post-mortem and placed in the palm of her left hand. But what actually killed her? It’s a puzzle that keeps Rizzoli and Isles busy for a while.

Then another murder occurs, and this time the victim has arrows protruding from his chest, though they didn’t kill him. Again, Rizzoli and her team are in the dark, until Isles has a brainwave that could start to make the pieces fall into place.

But what of the faceless, emotionless Holly? The more we learn of her, the more we realise she is the key to everything. She has a secret, and there’s no way she’s sharing it with anyone. There are several plotlines at play here and you’ll be doing well if you can keep track of them, because Tess Gerritsen is a mistress of sneaky subtleties.

Some series can start to fizzle out after about 12 books, but there’s more than enough in I Know a Secret to keep you engrossed. First, we have Rizzoli and Isles with their complex relationships, personal issues and personality quirks. They’re surrounded by a veritable cornucopia of supporting characters and are the definite stars of this show. Then there’s the cleverly conceived plot which is designed to keep you guessing for a long, long time  Coupled with a love/hate/unsure relationship with Holly, this is a book destined to keep you up to the wee small hours, determined to stop after ‘one more chapter’ but never quite managing it.

Best of all, I love the authenticity that an author who is also a physician can bring to the descriptions of both murder scenes and autopsies. I may have to watch TV hospital dramas and documentaries from behind a cushion, but reading such vivid scenarios brings out my bloodthirsty side and I lapped them up. The good news is that there are enough loose ends to guarantee book number 13. Bring it on!

I Know a Secret is out 10 August. Read our review of book number 11 in the series, Die Again. If you like multi-dimensional lead female characters, try The Chalk Pit by Elly Griffiths, featuring Dr Ruth Galloway. We recently interviewed Tess Gerritsen about the Rizzoli and Isles series.

Bantam Press
Print/Kindle/iBook
£9.99

CFL Rating: 5 Stars