A man is reported missing in the vast, rural Golspie region. Search dogs scan the forest, and multiple agencies are alerted in an attempt to find him before he comes to harm. His vulnerable state puts him at high risk, and no stone is left unturned in the search. However, three days in, the case takes a turn as police discover he is wanted for questioning by another police force.Meanwhile, the county lines drugs epidemic has reached its new frontier of Inverness. Specialist CID officers go undercover to raid two properties suspected to be hubs for dealing Class A drugs. On Skye, ex-Glasgow policeman Sgt Gordon McKay comes to the rescue of a stranded tourist who has injured her ankle on a trail in the hills.