In 2020, a Glasgow pathologist meets a Highland gamekeeper who seems perfect on paper. They're soon engaged — then a confession changes everything.

As Caroline's actions give police a new lead in a cold case, she enters a terrifying double life with the McKellars — and hopes Sandy still trusts her.

Torn between doing the right thing and protecting the man she can't walk away from, Caroline spirals as she desperately tries to avoid the witness stand.