CW's series "Supernatural" has left fans teetering at the ends of their seat as more twists from the lives of the Winchester brothers Dean (Jensen Ackles) and Sam (Jared Padalecki) are expected. The attractive brothers are up against many odds this season.

The official synopsis released by CW reveal that Charlie, whose character is depicted by actress Felicia Day, will make a surprise comeback this episode. Fans may recall her going to Oz in season nine, episode four titled "Slumber Party". Apparently, the brothers are tracking the Internet for suspicious supernatural activities when they stumble across a video that clearly shows Charlie beating a District Attorney. Shocked, the brothers speculate the reason she came back. Dean thinks she came back to hunt on her own. He assumes that the IT expert and now hunter may have beaten the District Attorney because he or she is a demon.

However, teasers expose the fact that the real reason Charlie returns will shock the brothers and fans. Images released by CW depict the brothers playing a "Good Cop, Bad Cop" routine to interrogate a chained Metatron. Other reports suggest that Charlie brings something "very dangerous" with her from Oz and she teams up with the Winchester brothers to hunt it down.

Reports also disclose that Dean will be on a murderous streak due to the effects of Mark of Cain on his body. He murders Claire's partner Randy, a loan shark and the men of the loan shark. This is witnessed by his brother, Castiel and Claire.

Sam and Castiel need to work together to remove Dean's Mark of Cain curse but whether or not they will be successful remains to be witnessed in the upcoming episode. Interested viewers should tune in to CW on Jan. 20 to see the unexpected return of Charlie.