When Lady Màiri Nic'Illeathain is murdered on the Isle of Harris, newly qualified family liaison officer PC Kat Crichton is assigned to the case.

A high-profile case like this is the career opportunity of a lifetime but for Kat, this is not just a job. A decade earlier, she got caught up in the twisted web of the MhicIllEathain family and was forced to flee the island. Ten years older, a resolute Kat now returns, determined to bring the killer to justice.

With the evidence at the sheiling matching Sir Douglas' new account of the night, DCI Halim is set on wrapping up the case. But Kat can't let her theory go - Sir Douglas is convincing, but Kat's sure it isn't the full story.

Meanwhile, Kat starts to suspect that the youngest son Ruaraidh's guarded behaviour at the sheiling yesterday was concealing something. In the hills above she finds charred remains of what appears to be Lady Mary's diary, and excerpts that hint at a deep betrayal in the family.