As the Snake Men prepare to awaken Serpos, new trouple is already brewing in Eternia. Evil-Lyn has allied herself with Count Marzo, and together they head towards the Well of Darkness to free Hordak from Despondos! Learning from Kobra Kahn of Marzo's plan, King Hssss and his Snake Men must abandon Serpos - for a time - in order to prevent the release of Hordak. Caught between two forces of evil, He-Man and the Masters must make their stand against the Snake Men even while thwarting the release of the ancient leader of the Horde...