Cade and the Empty Ark

They thought theirs was the only Ark.They were wrong.Cade is exploring farther and farther out. But he never thought he'd find this. The trees part, and there it is. Another Ark. They weren't alone! When he enters, though, no one greets him. The Ark is empty.What happened to everyone? Where did they go? And what happens when the Ark itself turns against him?