In the future, people have discovered that magic can occur through computation and mathematical methods. Thus, a government agency was formed to combat these instances. A worker at this company signs up to be the night duty officer on Christmas. This role requires him to man the phone in case any agents call for help or for other resources. While on his shift, the officer remembers the agency Christmas party, where a precognitive had interrupted the festivities to announce that this would be the last Christmas party ever, as he could not see further into the future. The officer tries to pay attention, but fails, as he is distracted by the meat pies. However, he is reminded of the precognitive again after conversing with a colleague who has no recollection of the speech at the party.

The officer begins to suspect that the precognitive at the agency, who operate under a forecasting department, foresaw a future that was so horrific that they wrote themselves out of existence to try to prevent that future. He deduces that if a monster comes to destroy the world, Christmas would be a great time because so many people believe in the magic of Christmas then. He believes the monster would take advantage of the strength of this belief to cross dimensions. He deduces that the monster would want to go down the chimney, and he comes up with a plan to expel the monster using inspiration from Christmas traditions.

The night duty officer rushes to the kitchen to grab some meat pies and lays down some pipes around the chimney. He encounters the ghost of the precognitive in the room with the chimney, and the precognitive admits that he is trapped in a time loop, having tried to prevent the terrible future by overwriting his existence. He warns the officer that the officer will fail, but the officer refuses to listen. When the monster comes down the chimney, it opens its mouth and inhales all the food. The officer then checks his pipes and turns on the furnace to burn the monster. It succeeds.