A desperate Kat realises Eilidh's close bond with Sir Douglas means she would be the only person who can find out the truth of what happened the night Lady Mary was murdered. But with no love lost between herself and Eilidh, can she convince her to help?

Kat investigates deep into Eilidh's past to uncover something that she hopes will make her waver. 
In a tense final exchange, Sir Douglas and Kat finally come face to face, as she confronts the demons of her past in an attempt to bring Lady Mary's 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.

Kat brings up the inconsistencies in Sir Douglas' story to her boss, but without hard evidence it feels flimsy. And when it's revealed eldest Maclean son Calum has a questionable alibi, he becomes the focus of the investigation. 

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.