“Doctor Who” Season 9 will bring back an old friend in episode 10. “Game of Thrones” actress Maisie Williams will return as the immortal Ashildr. After appearing in both the Viking and Victorian eras, fans will finally get to see her in the modern day, according to the latest synopsis.

It sounds like episode 10, titled “Face the Raven,” won’t be quite as scary as episode 9, which was inspired by horror movies. Episode 9 will put the Doctor (Peter Capaldi) and Clara (Jenna Coleman) back on Earth with an old friend, Rigsy (Joivan Wade). He met the time travelers in Season 8 when aliens were absorbing humans into walls and floors. It seems Rigsy has once again stumbled upon something that he shouldn’t have.

“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,” the synopsis reads. “Sheltered within are some of the most fearsome creatures of the universe ... and Ashildr (Maisie Williams)!”

Of course, they won’t just observe the alien world. They’ll somehow get into a little too much trouble. “With a death sentence hanging over their heads, not all of the intruders will get out alive,” the summary warns.

One trailer hints that this might be Clara’s last episode. Coleman announced her departure at the beginning of the season, but no one know exactly when she’ll leave. In the promo video below, she says goodbye to the Doctor. “Let me be brave,” she repeats to herself as she walks away from the Time Lord.

Watch the “Doctor Who” Season 9, episode 10 trailer below:

However, another trailer makes it seem as if Rigsy is the one facing the death sentence. A tattoo has suddenly appeared on him and the Doctor claims it means his death is imminent. “There’s no nice way to say you’re about to die,” the Doctor says.

Watch the promo video for “Doctor Who” Season 9, episode 10 below:

“Doctor Who” Season 9, episode 10 airs Saturday at 9 p.m. EST on BBC America.