It's the end of the world and a great flood is coming! Luckily for clumsy Nestrian Finny and his dad Dave, the human Noah has built an Ark to save all the animals of the world. From here on everything should be plain sailing... That is until Finny and a curious young Grymp named Leah fall off the Ark! With the Ark sailing off in to the distance, Finny and Leah along with some rather unusual new friends must go on the adventure of a lifetime if they ever hope to see their parents again.