Jack and Annie are off on another mythical mission at the request of Merlin the magician. Luckily, they have a young sorcerer, Teddy, to help them. From underwater caves to a Spider Queen, from mystical selkies to a magical sword, this is a Magic Tree House adventure kids won’t want to miss!

Jack and Annie travel in their magic tree house to the land of the mystical selkies to seek a magical sword for Merlin.