It begins with Danny riding home on his motor scooter, saying he was finally going to get home on time. However, as luck would have it, his ghost sense went off and he saw three ghost vultures. He went ghost and followed them, and the eventually told him they were after his dad. He manages to drive them away, but he's late yet again.
After that, his parents lecture him about this becoming a problem. Danny replies that they have no idea what it's like to be a kid, but Maddie disagrees, Jazz intervenes, saying Danny can't relate to them because they never spend time with him. Jack thinks about it and finally decides to take Jazz and Danny to their college reunion, held at Vlad Master's house. Jazz gets angry, especially since Jack's new invention fires ectoplasmic goo all over her face.
While on their drive to Wisconsin, Jazz complains to Danny while Jack lectures about the Fenton Ghost Assault Vehicle. Danny presses a button, hoping to open the window, and various weapons activate, firing all over the place.
That night, Jack tells them all about Vlad Masters, his best friend from college. There is a brief flashback with Jack narrating about the accident Vlad got into. He believes Vlad has finally forgiven him after all these years, or has he?
They finally reach Vlad's castle, where he greets them, and he's especially warm to Maddie. Jazz complains about the lack of fashion sense, while Danny says Vlad's a Packers fanatic. He then grows angry, saying Green Bay won't sell the Packers to him, then calms down and says that was one of two things his wealth has not, as of yet, gotten him. (While Looking at Maddie) Jazz and Danny are creaped out, but Danny is soon distracted by a signed football. While Vlad's lecturing about his prized possession, Jack tackles him from behind. He yells at Jack, saying he lost all his old moves in the hospital. He then calms down, saying he was holding the reunion here to reconnect with Jack. Then he says the Dairy King's ghost could haunt the castle, and Jack zips to the Fenton RV. Vlad smirks evilly.
That night, the ghost vultures attempt to bring Jack to Vlad. However, Danny stops them and the vultures scatter. Danny then says that was too easy, and Vlad, in ghost form, shows up. Danny attacked, but Vlad was too fast for him and threw him into the wall. He then goes through it, Danny following him.
Vlad laughed, and said he was the ghost boy who used his powers for good. Danny says he didn't want to fight him, and Vlad replied "No, no, you don't" He then blasts Danny with a pink ectoplasmic beam. Danny fires his own energy blast, desperate to defend himself, but Vlad blocks it easily. He then multiplies, saying he's had years of practice, but Danny wouldn't have any time for it. After taking a terrible hit, Danny struggles to get up, but Vlad beats him down, and through the door, where he changes back into a human. He stares in shock that the ghost boy was Jack's son, and then transforms back into Vlad.
Danny wakes up in his own room, Vlad asking what had happened. (Even though he already knew) After Danny giving Vlad a shaky answer, he leaves. The next day, the reunion starts, Jazz watching the history of the Packers, while Danny's with his parents, extremely bored, and embarrassed by his parents' actions. An old "friend" of Jack's, Harriet Chin, stood next to Danny, as shocked by Jack's behavior as Danny.
Vlad walks up to Danny and asks him to bring a present to his father from his lab. Danny agrees, but asks Vlad not to call him "son", as that privilege is reserved for his Dad. After Danny leaves, Vlad stares at Maddie, saying he lost his chance to be with her in college, but that was about to change.
Meanwhile, Danny's in the lab, and finds out that the picture of Jack the vultures had matches Vlad's picture. Danny goes ghost, after his ghost sense went off. He sees the ectopusses, the first ghosts he ever fought, and defeated them easily.
However, his problems weren't over. He was trapped in a ghost net by Skulker, but manages to break free, and kick Skulker aside, asking what he was doing. Skulker said he'd find out soon enough, and trapped him in an device he created that disrupted his powers.
As Skulker was about to kill him, Vlad stopped him, saying he didn't free Skulker so he could kill Danny. Skulker's PDA beeped and he had to leave again. Danny had many questions for Vlad, and Vlad responded that Danny was the second ghost hybrid Jack created. To clear things up, Vlad transformed into the ghost Danny fought the previous day.
Danny tries to go ghost, but can't, and Vlad mocks him. He then explains the invention's use, and told Danny of his plans, offering Danny a place by his side. Danny refused, and Vlad goes off, saying that he's see how he felt once Jack was out of the way.
Meanwhile, Harriet was telling Jack about where she went in her career as a reporter, while Jack looked like he could barely stay awake. Vlad overshadows him, and Jack (Vlad) throws her into the table. Maddie was furious, and Jack was saying that she chose wrong. After that, Jack started to fight back, and managed to gain control for a few seconds, but Vlad re-takes control.
Back in the lab, Danny was struggling to get free when a ghost shows up. To Danny's surprise, the ghost sets him free. He asks the ghost for help, but he says that kings don't fight, saying they sent other people to fight for them. Realizing he was going to fight Vlad alone, Danny goes ghost and flies off.
Vlad (in Jack's body) was causing chaos and attacking everyone who was left, saying to remember Jack Fenton did this to them. Danny showed up and managed to force Vlad out of Jack. They fought again, and Vlad offered apprenticeship again. Danny refused, firing an energy blast. Vlad sends it back at him, and Jack shows up in the Fenton RV, trying to stop Vlad, and failing. Vlad takes Maddie with him, and Jack follows, trying to save his wife.
Danny flies into the RV and tries to take control but nearly runs over his father. Finally, he starts aiming for Vlad, but nothing was effective until he used the ectoplasmic goo. Maddie started falling, but Danny, taking over Jack caught her. Then he told her to check on Harriet while he finished it.
He threatened to expose them both unless they agreed to a truce. Not having any choice, he accepts, falsely proclaiming Jack's superiority, and leaves, but not before saying "until next time, son." They left Vlad's castle, Danny telling his father about the positive things he saw in him, as Jack was upset about them growing apart since college. The episode ends with Jack saying Danny's curfew is still 10:00 PM.