After two bizarre but entertaining episodes, it’s time for the Doctor and Belinda to face a very scary situation. In this case, it’s a scary threat in the dark…from a place he’s been before.

SPOILERS BELOW

The Doctor gets involved in an investigation of a mining facility that seems to be deserted. Actually, the crew is dead and the mirrors are broken. The only person left is a cook named Aliss Fenty (Rose Ayling-Ellis). She is deaf but tells Shaya (Caoilfhionn Dunne) she had to kill someone or she’s be killed. She says the crew went mad because something emerged from the well where they were mining diamonds.

For the longest time, Shaya and her crew think Aliss is the threat, but she insists she is not. It’s whatever is behind her, as it tosses crew members and kills them. Rose does a wonderful job playing Aliss, an ordinary woman who is in the middle of a major threat. The entity uses that to grip the crew in paranoia before killing people. It’s also silent and invisible but shows itself just enough to cause doubt and fear.

But what is it?
The Doctor has an idea when Shaya tells him the planet used to be called Midnight. That was the setting for a 2008 episode where the same entity drove several people in a shuttle insane. He also figures out if someone gets directly behind Aliss, the entity kills. Cassio decides killing Aliss and capturing the entity should be done. It makes things worse.

The Doctor communicates with the entity, but only whispers are heard. Whatever it told him, it terrifies him.
It also gives him an idea. He tells Shaya to hit a pipe to release mercury so that the entity sees itself while they escape.
However, it just goes behind Belinda.
This is where the episode has a shocking ending that’s also imaginative: Shaya shoots at Belinda that almost kills her, but it’s enough for the entity to possess her. She then runs to the well, and falls to her death.
Does it kill the entity as well? Let’s just say there are whispers.

It was an experience that nearly overcomes Belinda but there’s something else. Even though the episode is set 500 thousand years in the future, the crew claims it never herd of Earth or the human race. She does tell the Doctor that maybe the reason she can’t go home is that it’s not there any more. He insists he will get her home, but the possibility has crossed her mind.

Oh, and Mrs. Flood (Anita Dobson) shows up again, this time as the commander who sent the crew to the mining camp. How does she do that, and keep people from figuring out that Ben is Glory?
Face it. She’s doing something similar.
Also, the planet where the Doctor arrived was loaded with Galvanic radiation that would have ruined the crew’s ship if they landed there.
So what? Remember when the Doctor split in two when the Toymaker showed up? Guess what kind of radiation was involved.
This might mean something.

The episode was a tense and scary story the season needed, and it was done well. It finally gets the Doctor and Belinda worried about whether Earth is still around. Eventually, they’ll wonder how Mrs. Flood keeps popping up.
Also, kudos for the show for having a deaf woman be cast as Aliss Fenty. The role could have been done by anyone, but making this move was a nice touch.

Next week, we find out Ruby Sunday has a new boyfriend. That’s not good news.