After tracking down the missing sister of her former partner Audrey, and helping to put an end to a monstrous being's reign of terror, one would think they'd find Prudence Osgood riding high. Instead, they couldn't find her at all.
A year and change after the events of Osgood as Gone, our titular hero has returned. Osgood is confused, exhausted, and dragging along more quirks than she ever remembers having. Her friends Zack and Audrey, the makeshift Spectral Inspector crew in her absence, don't quickly believe that things are back to normal, but have to admit that no one is quite as grumpy and belligerent as "their Osgood."
Unfortunately for all involved, something has hitched a ride back from the space between worlds, and not even Osgood can guess what its plans are. She will need to stand with her friends against a monstrous emergent evil, and it will take everything the Spectral Inspectors have to stop what's coming once the events are set in motion.
Can they keep their sanity, and stay alive? Find out in Osgood Riddance.