10-year-old Morten Viks wants to be just like his dad. He builds a model ship and dreams of a long sea voyage. Unexpectedly, he shrinks to insect size and becomes the boat's captain, but sailing turns out to be no simple matter.
A tree house by the sea is where Morten spends his free time writing letters to his father and hiding from his strict aunt Annabelle. He wants to go on an adventure and explore unknown lands. One day a nutty magician shows up in his port city and sprinkles Morten with a mysterious powder. The powder makes him tiny enough to move on board the miniature ship. However, he is not the only one aboard - the Queen of Spiders and her entourage are already the crew. Morten will have to be courageous to find a way to save the ship from sinking and discover a way to return to the real world. Captain Morten and the Spider Queen is a surprising animated film about the power of unlimited children's imagination.