As filming for the opening crime scene took place in a somewhat public area, crew followed Tom Ellis with an umbrella to keep bystanders from taking pictures of him in his orgy pants.
Both Mazikeen and Eve mention the name Lilith quite a few times. In some Jewish folklore, Lilith was Adam's first wife. She was created at the same time and from the same clay as Adam. Lilith left Adam after she refused to become subservient to him and then would not return to the Garden of Eden after she had coupled with the archangel Samael. Earlier in the series, it was revealed Lucifer's name was Samael before he left heaven.
According to Judeo-Christian lore, Remiel was a leader of the Fallen Angels. The Angels were thrown from heaven for mating with humans or teaching forbidden knowledge.
The name Castiel is referenced, which is the name of a very prominent angel on Supernatural (2005). The very next episode was directed by Richard Speight Jr., who plays the archangel Gabriel on Supernatural.
Episode name said by Lucifer.