A Chicago detective travels to Scotland after an emerging serial killer’s crimes match those that he investigated five years earlier, one of which was the crime scene of his murdered girlfriend.

When dysfunctional adult Al Clancy mistakenly agrees to mind his smart-ass 10-year-old nephew Karl for a week, his job and home are placed in jeopardy. In a bold bid to save Al’s job, they steal his mam’s camper van, become best friends, and embark on a criss cross adventure, putting up posters all over Ireland. When things go wrong and the lads get cranky, one of them realises that the other one needs to grow up.