During a school field trip to a museum, Danny translates the engraving on an ancient Norse rune stone and accidentally summons a Frost Giant. The Norse thunder god Thorarrives to aid Spider-Man's team, but magic from a medallion around the Giant's neck turns Thor into a talking frog. The team follow Thor to Asgard, where the power-hungryLoki is working with the Frost Giants to seize the Asgardian throne.