Teela's desire to find out who her mother is sets her on adventure into Crystal Sea region to find the Oracle. But Crystal Sea is home territory of Mer-Man and he has another plan in mind... to enact vengeance on Man-at-Arms who 20 years ago rescued a victim intended as a sacrifice for the sea demon Bakkull. Now, Mer-Man's plan is to capture Teela and sacrifice her to Bakkull. His plan comes to a halt when He-Man comes to a rescue.