A deadly criminal known as "Ragnarok" breaks out of the Null Void, and begins a search for a mysterious key. Meanwhile, Kevin returns home to find his house ransacked with his mom, who confesses the truth about Ragnarok. Kevin then asks Ben and Gwen if they know anything about Ragnarok, and when they tell him they don't he tells them to stay out of the situation. The two, now concerned, ask Grandpa Max if he knows anything about the escapee. He confesses of having a partner named Devin, who risked his life to stop Ragnarok several years back. His partner's full name was Devin Levin, Kevin's dad. Ben and Gwen track Kevin with his plumber's badge and together force Ragnarok to flee. Gwen then helps Kevin find the "key", but Ragnarok steals it, then teleports to his ship. Ben, Gwen, and Kevin manage to transport themselves via the same signal, but before they find Ragnarok, Kevin tricks the other two to get into an escape pod. With Ben and Gwen descending down to Earth, Kevin can have his revenge. He and Ragnarok battle, while Kevin causes the entire ship to destabilize into a vortex. Ragnarok begs Kevin to save him, stating that his father would to. Despite his desperation, Kevin merely takes his key and lets him get sucked into the vortex. When Ben and Gwen ask what happened, he simply states that Ragnarok didn't make it.