The town of Amity Park is thrown into chaos by the town's first mass invasion of ghosts. It's all part of the plan by Ghost Zone's top Sheriff, Walker, to capture and incarcerate Danny Phantom. As first Danny battles, then befriends, a hulking ghost named Wulf, Walker and his goons "overshadow" most of the people in Danny's inner circle. While eluding attacks from his ghost fighting parents, Danny defeats Walker and restores calm in the city, earning the title of "Public Ghost Enemy #1" in the process!
When Paulina sees Danny transform into his ghostly alter-ego, he fears that she'll tell everyone. But not only does Paulina agree to keep Danny's secret, she becomes his girlfriend! Unfortuately for Danny, Paulina is being overshadowed by Kitty (Johnny 13's girlfriend) in an attempt to make Johnny jealous after a fight. And if Danny ruins Kitty's plans by turning her down, she'll (as Paulina) tell the entire town that he's the Ghost Boy!
In an attempt to bond with her distant son, Maddie takes Danny to a science symposium in Florida. However, it's all a ruse by Vlad Masters- Danny's archenemy! He plans to convince Danny and Maddie to stay with him. At the same time, he launches a huge ghost attack on Fenton Works, hoping to eliminate Jack!
After having a fight with Danny, Sam utters the words "There are days I wish I never met you" as she leaves. This wish is granted by Deisree, and the next day, Sam discovers that Danny has no idea who she is! Unfortunately, since Sam prodded Danny into checking out the Fenton Portal, he doesn't have any powers. Now, Sam must convince Danny back into the portal for another "accident" so that he can become Danny Phantom!