In 2022, Guard and Thunder live on Earth, managing alien prisoners locked up in humans. One day, a spacecraft appears in Seoul, and Detective Moon catches a strange sight. Meanwhile, 630 years earlier in Goryeo, Muruk and Ean scramble to win the huge reward for the Divine Blade. The two sorcerers, Madam Black and Mr. Blue, as well as the masked Jajang, also set out on a race to find the Blade.