Lissa is a nurse in a gritty, hectic London neighborhood. Always terribly competent and good at keeping it all together, she's been suffering quietly with PTSD after helping to save the victim of a shocking crime. Her supervisor quietly arranges for Lissa to spend a few months doing a much less demanding job in the little town of Kirrinfeif in the Scottish Highlands, hoping that the change of scenery will help her heal. Lissa will be swapping places with Cormack, an Army veteran who's Kirrinfeif's easygoing nurse/paramedic/all-purpose medical man.