Episode 15 of CW's "The Vampire Diaries" revealed some shocking moments including Bonnie's arrival to present day Mystic Falls, Caroline flipping her humanity switch and Damon realizing his mother is stuck in a prison world. Avid viewers are waiting with bated breath for episode 16 aptly named "The Downward Spiral".

The episode's synopsis, as reported by WetPaint, reveals that Caroline gives her friends an unexpected ultimatum and the Mystic Falls gang won't know how to deal with it. Stephan is at a loss on how to handle the non-humane side of Caroline. He attempts to intervene but it backfires and sets off a dangerous chain of events. How could Stephan have made the situation worse?

Elena and Stephan are forced to race against the clock. While the two take care of Caroline, Damon wants answers and asks Kai for them. Unfortunately, Kai's information about the prison world turns his life upside down when he hears some devastating news about his mother, Lily. What could this news be? Surely, if Bonnie could get out of prison world, maybe there is a way that she can too?

Enzo continues to be interested in Sarah Salvatore while Bonnie struggles with the effects of being back in present day Mystic Falls. That seems natural as she was stuck in 1994 for over 200 days and even tried to kill herself.

In an interview with TVGuide executive producer Julie Plec states that Bonnie's return to Mystic Falls won't be easy. She said, "Bonnie is going to come back having the scars of what she went through and the post-traumatic stress of having no one to talk to. She'll be dealing with the psychological ramifications, (which is) not something she'll be advertising."

Episode 16 will also mark actor Ian Somerhalder's directorial debut. "The Downward Spiral" will air on Thursday, March 12 on CW at 8 p.m. ET.