Skulker, a predatory ghost hunting legend who fancies himself a collector of all things rare and unique, has set his sights on Danny Phantom, the world's only half-ghost/half-human hybrid. The games begin, as good and evil ghosts face off.

Danny meets his evil opposite in Vlad Plasmius, a childhood rival of his ghost-hunting dad, Jack. Unfortunately, Vlad acquired ghostly powers 20 years ago, which means he's stronger and more experienced than Danny -- and hell-bent on taking everything away from Jack Fenton including his life.

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.