The Forever Knights discover an ancient seal with their insignia and break it open, accidentally unleashing a mysterious creature which kidnaps some of them and flees. Tracking a disturbance in the mana field, Gwen, Ben, and Kevin reach the site of the seal and agree to aid the Forever Knights in finding the creature. They find the creature in the city, where it uses its tentacles to momentarily seize control of Gwen’s mind, then escapes. Gwen, who has connected to the creature, reveals that it calls itself “Lucubra” and it originated from another dimension. Winston, a Forever Knight squire, reveals that the First Knight – the founder of the Forever Knights – captured the Lucubra in the seal centuries ago. Ben’s team follows the Lucubra to a warehouse, but Gwen falls under its influence again, prompting Ben and Kevin to tell her to sit out the fight. They attack the Lucubra along with the Forever Knights, and Gwen is ultimately able to send it back to its dimension. The Knights and the team part ways, but as they leave, Winston is revealed to still be under the Lucubra’s influence. Meanwhile, at a retirement home, a mysterious old man senses that the seal has been broken.
