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.

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!