- Are there angels among us?
- Sam believes in angels, while Dean thinks something evil is behind everything.
- When Zack's room is shaking and his TV falls over you can clearly see that the power cord is neatly tied up and unplugged.
- Dean tells Sam that while listening to the police scanner he heard that Zack stabbed a victim in the heart, but the stabbing was actually in the lower gut.
- According to Dean's cellular phone listing, he's playing Kashmir by Led Zeppelin, but he's actually playing Down On Love by Jamie Dunlap.
- Bob Dylan - "Knocking on Heavens Door"
- Jamie Dunlap - "Down on Love"
- The title, Houses of the Holy, is the title of a Led Zeppelin album and is also the title of a song off of the album Physical Graffiti.
- Dean: Yup, Roma Downey made him do it.This is a reference to the TV show, Touched by an Angel, in which Roma Downey plays an angel named Monica who helps people
- Dean: We'll just put it Spongebob-side down.Referencing the popular Nickelodeon animated TV show, SpongeBob SquarePants, and the main character, a yellow sponge that wears pants, works as a fry cook, and lives in a pineapple under the sea.
The lost week. Sam disappears, loses seven days and wakes up covered with blood. The brothers investigate - and every clue leads them to believe that Sam's dark side may have finally emerged.
BORN UNDER A BAD SIGN
