It's time for Danny and his classmates to take their Career Aptitude Test (C.A.T.), and of course Danny is freaking out. He's been so busy hunting ghosts that he hasn't had any time to study or even think about his future. But, far in the distant reaches of the Ghost Zone, places no one has even heard of, a pair of beings called the Observants have been keeping an eye on Danny's future for him, and they don't like what they see. Danny finds a way to cheat on the test, well, he had a choice; to cheat or not to cheat, and since he never studied, he had no choice but to cheat. Danny's decision causes a tragic chain reaction that spells doom his family, friends, for all of Amity Park, and himself. Now, they are sending a ghost named Clockwork, who has the power to control time, to do anything it takes to stop Danny from heading down the path that will ultimately cause him to renounce his humanity and turn into the evil Dark Danny. Can Danny, with the help of Sam, Tucker, Jazz, and a new power, prevent the inevitable and change of the entire worlds future? Or, will the evil Dark Danny find a way to travel ten years back in time to insure that a tragedy occurs that hurts 14-year-old Danny Fenton so deeply that his only choice will be to turn to the dark side forever?