The episode follows a researcher examining archived correspondence from 1916-1917 involving a woman named Delilah P. and Magistrix Colchester. The letters reveal that the British Department of Orthogonal Research (DOOR) was conducting secret negotiations with Hearn, a lord of the Wild Hunt, to use supernatural forces against German forces in World War I. The price demanded by Hearn was horrific: 100 children to take to otherworldly realms, 100 soldiers' souls to join his hunt, and 100 women for his fairy riders. The British officials planned to source these victims from orphanages, hospitals, and brothels. Delilah P., working as a secretary for Mr. Abernathy who was drafting the contract, became horrified by the plan. She secretly modified the contract with stipulations that would cause DOOR to break the agreement almost immediately, making the deal null and void. Knowing the Wild Hunt might detect her sabotage, she offered herself as additional collateral to ensure the contract's failure. After sending her final correspondence, Delilah disappeared, paying her neighbor 100 pounds to care for her cat. The next morning, the entire DOOR department was found dead from apparent carbon monoxide poisoning. Two weeks later, farmers reported Wild Hunt sightings along the River Neen, with witnesses noting a woman riding at the head of the hunt alongside the horned lord. The woman matched Delilah's description, and her status was officially changed to 'retired' with a new 'P' appointed to replace her. The documents suggest that Delilah successfully prevented the sacrifice of innocents by joining the Wild Hunt herself, becoming part of the supernatural force to ensure it would never serve the British government's purposes.
