Spoilers and teaser photos are out for Doctor Who's Episode 9 entitled 'Face the Raven.' In the preview, An old friend Rigsy who appeared in last year's 'Flatline,' joins the doctor and Clara in a magical world found discreetly in the heart of London. Time is of great essence for Doctor Who as Rigsy's life is threatened.

The episode is a follow up of last week's over the edge 'Sleep No More.' This week, Ashildr (Maisie Williams from 'Game of Thrones') is back and she is very much present in the teaser photos that BBC has released. Here is the official synopsis: "The Doctor and Clara, with their old friend Rigsy, find themselves in a magical alien world, hidden on a street in the heart of London. Sheltered within are some of the most fearsome creatures of the universe... and Ashildr (Maisie Williams)! With a death sentence hanging over their heads, not all of the intruders will get out alive."

While there are characters that will make a comeback, one of the major roles in the series, the Doctor's trusted companion, Clara Oswald (Jenna Coleman), is leaving for good. Jenna was reported to exit before the Christmas special to focus on her new role in an ITV Drama as Queen Victoria. 'Face the Raven' will officially be the last time Coleman will play as the doctor's loyal assistant.

According to South Wales Evening Post, Peter Capaldi who plays the lead character in Doctor Who, confirmed that this Saturday's episode would yield Clara's permanent departure, and that fans should expect a tragic end for her. "It's the end of her story. I don't want to go into the details of it, but it's sad," he shares. "It's a sad one, gripping and very strange."

When asked if the character might make a comeback, Capaldi said that sometimes people can't come back and that things happen that they can't return from.

Doctor Who airs Saturdays at 9 p.m. ET on BBC America.