Danny fears he's going to cause his parents' break-up when he knocks Jack's anniversary gift into the Ghost Zone. Desperate to retrieve it, he dives into a ghostly dimension where he runs afoul of Walker, the ghost warden of a ghost jail, and is thrown into prison with every ghost he's ever caught.

When Paulina witnesses Danny's ghost transformation, he fears the exposure. Imagine his surprise when Paulina swears to keep his secret - then becomes his girlfriend! Life is great for Danny, until he finds out that Paulina has actually been overshadowed by Johnny 13's girlfriend, Kitty, in her plot to make Johnny jealous. Danny reluctantly plays along to protect his own identity, but, when Kitty's welcome wears thin, Danny pleads with Johnny 13 to take her back. When Kitty abandons Paulina's body and goes back to her true love, Paulina resumes her indifference towards Danny Fenton - although she's now madly in love with Danny Phantom!

Maddie relishes the chance to bond with emotionally distant Danny at a weekend mother/son science seminar. However, the seminar is a ruse orchestrated by Vlad Masters - a.k.a. Vlad Plasmius, Danny's arch enemy! Vlad's plan is to convince Maddie and Danny to live with him while simultaneously destroying Jack with a massive ghost attack. When Vlad short-circuits Danny's powers, Danny gets to witness Maddie's impressive ghost fighting prowess. Meanwhile, a reluctant Jazz is pressed into ghost-fighting duty with Jack - and likes it, in spite of herself!

Danny and Valerie Gray are forced to become ""parents"" to a sack of flour for a one-week school assignment. At the same time Skulker, ghost hunter extraordinaire, decides to pit Valerie and Danny Phantom against each other in a contest - with the winner earning the privilege of becoming his prey. When Skulker's orchestrated contest ends in a tie, he handcuffs Danny and Valerie and hunts them both through the Ghost Zone. In order to survive, Danny and Valerie learn to let go of their mutual dislike and cooperate with each other - which may just affect their relationship in the real world. Or, not.

When Vlad Masters' ghost portal explodes, he schemes to replace it by stealing Jack Fenton's portal. As a distraction, Vlad anonymously offers a million dollar bounty to eliminate Danny Phantom. As ghost hunters from around the world gather in Amity Park to hunt the ghost kid, Danny sacrifices himself to Jack - both to win the prize money for Dad and to bolster Jack's inept reputation, which embarrasses Danny. However, when his family's life is put in jeopardy, Jack needs no help from Danny to save the day on his own.

Sam rebels when her overprotective parents forbid her from attending the strange Goth circus that's come to town. Little does she know that the circus performers are ghosts, under the mystical control of the creepy ringmaster named Freakshow, who also uses the ghosts to loot the town. When Danny falls under Freakshow's spell and joins the circus - and the robbery spree - Sam must operate under the radar to destroy Freakshow's magic crystal ball, free Danny and get grounded, big-time.

Danny and Sam get into a fight, and when Sam utters the words, "I sometimes wish I'd never met you," she finds herself in a world in which she and Danny are strangers. Worse than that, since it was Sam who encouraged Danny to check out the Fenton Portal the night he got his ghost powers, Danny doesn't have any powers! Now, Sam must convince Danny that they share a friendship and a history, and lead him back to the Fenton Portal for a second "accident" so he can again become Danny Phantom.

After being bitten by tiny green ghost beetles, the kids of Casper High get a mysterious illness that gives them ghost powers and are quarantined at a spooky old hospital outside of town. When Danny sneaks into the hospital to investigate, he is captured by Penelope Spectra and her assistant, Bertrand. They are the ones who started this illness as part of their plan to build Penelope a young and beautiful new body. All she needs is Danny's half-human/half-ghost DNA to complete her ghostly plan. With Danny captured and Sam sick, it's up to Tucker to conquer his fear of hospitals and free Danny before Penelope gets what she's after.

Tucker's running for student body president, but no one's paying his campaign any notice, and that includes his campaign managers: Danny and Sam. On a field trip to a museum to look at ancient Egyptian artifacts, everyone is surprised that the pharaoh in question looks just like Tucker. And when Tucker looks in a ghostly mirror, his image brings the pharaoh's minion, Hotep Ra, to life! Hotep Ra bows before Tucker and becomes his servant, urging him to not stand by anymore and be ignored. Tucker's new attitude -- with help from his new king's scepter -- gets him even more respect than he expected when he accidentally transports his friends and classmates to ancient Egypt during a school debate. Now, Tucker is a king, and it's hard not to enjoy the perks. Unfortunately, the servant Hotep Ra has his eye on Tucker's throne and some sinister plans in mind for the students of Casper High.

School's out and Danny has nothing on his mind except a relaxing, fun and a ghost-free summer vacation. His dream is quickly destroyed when Freakshow, the villainous ringmaster with ghostly minions, escapes from jail. Danny, caught off guard, is forced to forfeit his summer plans when Freakshow manages to reveal Danny's secret identity to the entire world! To make matters worse, Freakshow kidnaps Danny, Sam and Tucker's families and uses them as pawns in this evil game of revenge. Now, on the run and hiding from everyone, Danny must rely on his powers to stay free, fulfill Freakshow's ransom demands and save his parents. With Tucker and Sam by his side, Danny travels cross-country to track down three "Reality Gems," which, when combined, will give Freakshow the power to turn Danny's world into his very own nightmare circus! As the sun sets in the west, Danny's enemies close in on him and Freakshow forces the hands of time closer to the fate of DOOM!

After getting lost in the ghost zone, Danny and his friends find in a frozen zone the Infimap, a map that lets the holder to travel everywhere in the ghost zone. After Vlad Masters steals the map, Danny, Sam and Tucker must chase him through different times and places, from Salem to ancient Rome, to get this treasure before he manages to conquer Earth.

Danny and Vlad’s game of revenge against each other begins with childish pranks, and, unfortunately for Danny, ends when Vlad decides to run for mayor of Amity Park! By overshadowing voters, Vlad wins in a landslide. The new mayor is eager to use his new power to make life as miserable as possible for Danny and his friends. He shuts down the Nasty Burger, outlaws technology, creates new school uniforms, and passes so many new laws in the name of “protecting the children” that Danny finds it impossible to go ghost.

Danny's class goes to a camping trip with Mr. Lancer and Ms. Teslaff to an abandoned place which is seemingly haunted. Soon reports of monster sightings and missing students have the whole camp shook up. Monsters start showing up and disrupting the camping trip. To Danny's surprise, these monsters are ghosts working for Walker, on the hunt for Wulf. Now Danny must save his old friend and his class from Walker!

Danny, after being publicly shamed by Vlad's new ghost hunting team, wants to be normal again. So he gets rid of his powers by reactivating the Fenton Portal after Jack dismantles it for a software upgrade. However, an asteroid made of Ectoranium threatens the Earth, and Vlad - after revealing to everyone that he is Plasmius - fails to stop it. The world now relies on a powerless Danny to get help from the ghosts in the Ghost Zone!