Bleeding Heart Yard - Elly Griffiths

DS Cassie Fitzgerald has a secret - but it's one she's deleted from her memory. In the 1990s when she was at school, she and her friends killed a fellow pupil. Thirty years later, Cassie is happily married and loves her job as a police officer.

One day her husband persuades her to go to a school reunion and another ex-pupil, Garfield Rice, is found dead, supposedly from a drug overdose. As Garfield was an eminent MP and the investigation is high profile, it's headed by Cassie's new boss, DI Harbinder Kaur. The trouble is, Cassie can't shake the feeling that one of her old friends has killed again.

Is Cassie right, or was Garfield murdered by one of his political cronies? It's in Cassie's interest to skew the investigation so that it looks like the latter and she seems to be succeeding.

Until someone else is killed...