"Pretty Little Liars" actress Kara Royster will be guest starring in an upcoming episode of "Supernatural" Season 12. While Ruth Connell returns in a different character. In addition to that, the official plot summary of episode 2 "Mamma Mia" has been released by The CW.

"Pretty Little Liars" actress Kara Royster has officially booked a guest role in "Supernatural" Season 12. The 22-year old African-American actress will portray the guest character of Alicia.

Alicia is a hunter who was raised by a witch, she also happens to be the sister of Max Miller (Brendan Fletcher). She will debut in episode 6 titled "It's Time for a Hunter's Wake" as she crosses paths with Sam Winchester (Jared Padalecki) and Dean Winchester (Jensen Ackles), Just Jared has learned.

Aside from that, Ruth Connell will make a come back in the next episode of "Supernatural" Season 12. According to Melty, the 37-year old Scottish producer, theater, TV, and film actress will resurrect and bring a different character in the show.

Ruth Connell plays the role of Rowena MacLeod, an extremely powerful and naturally-born witch. She is the mother of Fergus Roderick MacLeod, also known as Crowley in the Underworld. Rowena first appeared in "Supernatural" Season 10 and died in season 11.

As for the official plot synopsis of "Supernatural" Season 12 episode 2, Spoiler TV notes, "Dean, Castiel (Misha Collins), and Mary Winchester (Samantha Smith) have a lead on Sam and set out to rescue him. Dean is uncomfortable with putting Mary in danger but she insists on going along.

Meanwhile, Crowley (Mark A. Sheppard) is tipped off that Lucifer has taken over the body of rock star Vince Vicente (Rick Springfield)." 

"Supernatural" Season 12 episode 2 is titled as "Mamma Mia". The upcoming episode is scheduled to premiere on October 20, 2016, at 9:00 p.m. EDT first and exclusive on The CW.