The dagger that Victor Drake gives Nigel is said to have belonged to Count Báthory. This is an allusion to Countess Elizabeth Báthory de Ecsed who purportedly bathed in the blood of virgins to retain her youth. The episode incorrectly states that Báthory was male.
Sam compares this leap to a Stephen King novel. He previously met King as a 17-year-old boy in The Boogieman - October 31, 1964 (1990).
This is the only episode not to feature any American characters other than Sam and Al.