The day has arrived for the great fjord regatta. The Mousekings are competing to see who is the best sailor! Fortunately, only the sea Mousekings can participate, or at least that's what Geronimord thinks... until he is swept onto Olaf's boat, where he will get tangled in an ocean of trouble! However, no one will pay much attention, because the Dragons are ready to attack again... In the distant North, in a mysterious archipelago, lives a people of rodents who fear nothing, except dragons... The Mousekings! They are all tall, strong, and brave, all except for Geronimord. He is the intellectual of the village, and his dream is to win a Mouseking helmet and... the heart of the beautiful Turphina!