This episode is one of the very few times when one of the sisters, Piper in this case, calls Prue "Prudence," possibly because of the seriousness and danger of the situation.
Originally the role of Bane Jessup played by Antonio Sabato Jr. in episode "Ms. Hellfire" was supposed to be filled by actor Richard Grieco but Charmed actress/producer Shannen Doherty objected to the casting and was quickly supported in that decision by fellow stars Alyssa Milano and Holly Marie Combs.
2nd appearance of the Demon Of Fear(played by Billy Drago) however this is the first episode in which he is referred to as Barbas.
Piper freezes Marci Steadwell- a good witch, but good witches don't freeze. However Marci is not a magical witch, rather a Wiccan practitioner and therefore mortal. Mortals do freeze.
This episode was released on the 13th of January 2000, as the episode did take place on a Friday the 13th. But the airtime was premiered on Thursday the 13th, not Friday.