Here’s it in a nutshell:

While Freddy, Bonnie and Chica enjoy their lives as pizzeria mascots, Foxy back in the pirate cove has been out of order for a whole year. Tired of the reality that he will never be fixed or put back in order, he comes up with a plan to salvage the other animatronics to fix himself, all the while making the rest of the band out of order and his fame revived by the “miracle machinery”. The three main animatronics, after learning his plan, get help from the night guard to stop Foxy from dismantling them. After Foxy is defeated, not killed (however you want, really), the animatronics are not only back to their normal routine, but they’re deemed as heroes and even more famous and loved than before. They get their whole pizzeria and themselves a major makeover. As for Foxy, he is dressed up in a humiliating outfit and is to be torn apart and put back together in the, not pirate’s, but KID’S cove, Freddy, Bonnie, Chica and Mike live happily ever after.