When Max dozes off before a double feature, Ben and Gwen are left to save the drive-in by themselves as the evil magician Hex brings the movie monster “That” to life, and unleashes him on the unsuspecting moviegoers.
The episode begins with the Tennysons at a drive in movie theater. They're watching a film with a monster in it, and Ben claims that these old films are dumb, and they all have the same formula. Gwen states that these films created the formula, and its the "same formula" for the first time. Max states that he's pretty sure how the story ends, and he falls asleep stating that his dreams are always interesting.
Inside the projector's room, Hex teleports in and kicks the worker out. He then walks up to the projector as he states he's running out of time, and he needs a seeker now. He looks up at the film and spots the "That" He claims it'll have to do. So Hex uses the Eye of Wotan to bring the creature from out of the film. The creature escapes and starts feeding on light. Ben then transforms into Diamondhead and fights the monster. The light reflects off Diamondhead, and he uses it to his advantage. He thinks that overfeeding the monster light will make it blow up. However, the monster on gets bigger. Ben times out, and the monster bursts into a cave where he finds more light. Ben and Gwen chase after it.
Meanwhile, Hex is angered that Ben feed the monster too much light, and it's going to drain the whole world before he can move forward with his plan. His power then begins to drain even further. Ben and Gwen find the monster, and they notice that it's changing as it eats more light. Ben transforms into Omni-Enhanced XLR8 to make it explode. The monster chases OE XLR8 around, and he uses the room to defeat the monster. The monster is now at an even more hideous form. OE XLR8 starts to feed it even more energy, and he eventually times out. The monster runs away yet again. Ben is ready to go back to the movies, but Hex arrives stating that it's too late. Ben and Gwen asks Hex about the monster. Hex explains that his continued existence on this plane necessitates that once every hundred years he activate the Eye of Wotan, and give life to a seeker. These beasts rely on their insatiable thirst to seek out ripples in the veil and tear through the fabric of reality into the Gates of Light. By submerging himself in the well that lies within, his earthly body is revitalized and his powers are renewed. But now that the creature has drained this well, Hex is doomed. He then explains that the creature will continue to feed until all the light in their realm has been consumed. Ben questions how they're supposed to stop it, and Hex claims they can't. Ben he can deaminate the creature using the Eye of Wotan.
Ben and Gwen talk. Ben thinks Hex will turn on them once he gets what he wants. Gwen then states that they need to help Hex. Ben then gets an idea. Ben as Wildvine uses Hex as bait to get the monster's attention. Wildvine throws Hex inside the creature's mouth, and Hex manages to destroy it. Hex emerges at full power. He then attacks Ben, how times out. Ben states that he can't believe he saved his life. Hex then realizes that his power depends upon forces that cannot overlook a life debt. Hex tells Ben not to expect restraint once they meet again. Gwen then arrives asking if Ben is okay. The two then realizes they left Max at the theater. They then run back, and sit down like nothing ever happened. Max then wakes up, question how the movie went. Ben claims it was surprising, and they're now ready to head out.
Eye of Wotan burning bright, give the seeker gift of sight, spare me from eternal night, guide its hunger, and free me to the gates of light.
Ben: Hey, hey! What's the deal with the whole light-eating monster thing? Hex: It doesn't matter now. It's over. Ben: Okay, you heard him. Let's go. Gwen: You said you were too late. Too Late for what? Ben: Come on. We're gonna need more to work with. Hex: Oh, very well. Listen closely because I won't be able to do this again. My continued existence on this plane necessitates that once every hundred years I activate the Eye of Wotan and give life to a seeker. These beasts rely on their insatiable thirst to seek out ripples in the veil and tear through the fabric of reality into the Gates of Light. By submerging myself in the well that lies within, my earthly body is revitalized and my powers are renewed. But now that the creature has drained this well, I am doomed.