
Technus is back, with a new plan to beam himself up to a super satellite and take over the world, and he's going to use Axion Labs to do it. As Danny Phantom battles Technus, Danny Fenton begins battling his feelings for Valerie, whose dad is back in charge at Axion. Sam and Tucker are surprised when Danny confesses he's thinking of asking Valerie to go steady. Unfortunately, as Technus puts his plan into action at Axion Labs, Valerie realizes her role as ghost hunter is putting her family and friends in danger. Can romance work between two kids with secret identities, or will the ghost boy and the ghost hunter end up breaking each others' hearts?
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.