Unraveling - S1-E7
Trivia: Christina is thrown out of her house after the revelation that she's been lying about her life, and leaves town on a Greyhound as the camera pans down to reveal a sign saying "Now leaving Point Pleasant. Please come back soon.". This is almost identical (both the shot of the sign and the story behind it) to the Buffy The Vampire Slayer episode "Becoming" (2x21) - both the show's executive producer (Marti Noxon) and the writer of this episode (Diego Gutierrez) are former BtVS writers.