An ambassador from another kingdom visits the Royal Palace to present King Randor with a gift. But Man-At-Arms recognises the man as Skeletor in disguise, and in an attempt to stop him, is turned into a crystal statue. He-Man and Teela must journey to the Isles of Darksmoke, where the great and ancient dragon Granamyr knows the only spell to reverse the effect on Man-At-Arms.

But their task proves far from easy- for not only is Granamyr suspicious of humans and reluctant to help them, but he says he will only give them the spell if they cut down the living tree named Skytree. Will He-Man willingly take a life if it is the only way to save that of his friend?