When the Rust Bucket runs out of gas on a foggy East Coast road, Ben, Gwen and Max are forced to stay at a hotel being menaced by Creepy Carl, a local folklore expert, who may actually be a ghost!
The episode begins with the Tennysons riding through the dark in the Rustbucket. Gwen states that they're in Harrowing Harbor, which is apparently the most haunted town on the East Cost. Ben, however, is scared. They arrive at a gas station near by, but Ben is frightened. They hear a voice nearby saying "you shouldn't be here". Ben, scared, transforms into Cannonbolt. The guy steps through telling them that they need to leave. Max, however, tells him that they need gas. He reads the nametag, which reveals his name to be Carl with a "C". Gwen spots a hotel in the distance, however, Carl explains that they shouldn't go there, and no one survives long enough to get their free breakfast. Max is immediately sold at the free breakfast offer, and decide to stay their. Ben still think's it's a bad idea.
The three walk up to the hotel while Gwen explains to Ben that there's nothing to worry about. Karl with a "K" walks through and welcomes them into the hotel. As they walk through the hallways, Ben spots a chest and Karl explains that it's made to trap ghost. Ben spots all sorts of creepy things as they walk through the Hotel. Once they finally make it to their rooms, Max and Gwen walk in tired, while Ben is still scared. Max tells him not to let his imagination get the best of him. A ghost appears behind Ben, and tells him to leave.
Ben lays in his bed, and keeps spotting scary things. Eventually, the ghost he spotted earlier attempts to stab him. He tries to transform into Cannonbolt, but gets Upgrade instead. He finds armor to enhance, and he manages to knock him off the balcony right before he times out. He wakes up Max and Gwen to show them the ghost. However, the ghost is gone. They decide to trap the ghost in the chest Karl showed them earlier, by using Ben as bait. They manage to catch the ghost in the chest. They hear a familiar vice and they open it only to spot Carl. Carl claims that he isn't working with his brother, and that he's trying to help him. The Tennysons, however, aren't buying it. From the distance, Karl laughs, announcing that he's going to eat them. He says that he's been turned into a monster and his brother was turned into a ghost because they were dabbling in dark magic. Karl transforms into a full monster, and he attacks everyone. Ben transforms into Wildvine to fight him. Wildvine struggles, and Max helps up Carl. Carl joins the fight to defeat his brother. Gwen points out the lure on Karl's head is the source of his power, so Wildvine throws a harpoon at it.
Once the lure is destroyed, a wormhole sucks Karl in. It begins sucking everything in the building in while Wildvine holds on to Gwen. They attempt to help Carl, but he decides to go willingly. Max also begins to get sucked in, but Wildvine saves him. The three escape the hotel, and the entire thing is sucked in. All three of them make it out safely.
The line where Carl says "And I would have too, if it wasn't for that kid turning into aliens" is a homage to the popular Scooby-Doo quote "And I would have gotten away with it too, if it weren't for you meddling kids".
When Ben and Gwen try to save Carl, he refuses saying "You already have". This is a reference to Return of the Jedi where, after taking heavy damage to his life support system defeating the Emperor, Darth Vader encouraged his son Luke to escape, refusing his son's desire to save him by saying "You already have, Luke".
Ben, Gwen, And Grandpa Max are behaving like the characters from Scooby-Doo. Max acts dumb-founded like Fred, Gwen acts spectral like Velma, and Ben is scared like Shaggy and Scooby-Doo.