Julia, 11, lives with her divorced father in Stockholm; her mother is in southern Sweden with a new man. Martin lives with his divorced mother in Stockholm, while his dad is on a remote farm in the north. Where Julia is impulsive, Martin is shy. When the two meet en route to weekends with their absent parents, they realize they're dead ringers for each other and exchange airline tickets, taking on each other's identity. At first, the respective parents even think their kids have changed for the better.