In the first ever crossover episode, Zak and Zoe join forces with Hawaiian visitors Luke and Lani, to find out who killed a historian visiting Ashton Falls in order to find a treasure map left by his grandfather a hundred years earlier. Meanwhile, Ellie and Levi move in with Zak and Zoe while the boathouse is being renovated and Alex helps Ellie prepare the nursery for baby Eli who is due to be born any day. Throw in some humor and Easter fun and you have a Zak and Zoe crossover mystery.