For once, the Doctor has to rely on someone else to battle aliens. He’s stuck in a shrinking TARDIS thanks to some two-dimensional aliens, and has to let Clara be him to fight them.

SPOILERS AHEAD…

It starts with a man in Bristol, calling the cops claiming there’s something in his apartment, about to attack him. Suddenly, he disappears, and what seems to be his face is on the wall.

The TARDIS soon lands there, but the Doctor discovers that his ship is suddenly half as big as it should be. That hasn’t happened since “Logopolis” in 1981. The interior is still big but the exterior is shrinking. Clara’s upset they landed in Bristol, not London, but he says she shouldn’t ruin the experience of not knowing something. They meet a kid named Rigsy (Joivan Wade), who’s serving community service because of his creative graffiti. He also says people had been disappearing from the estate, including his aunt, but the police haven’t done much.  There’s also figures painted in the walls of a nearby tunnel..but were they painted?

When Clara gets back to the TARDIS,  it’s the size of a bobblehead. She finds it pretty amusing, but the Doctor doesn’t, since he’s stuck inside.  She’s given his psychic paper and sonic screwdriver, plus some nanotech, to be the Doctor by proxy. She even calls herself a “Doctor”, which also doesn’t amuse him. Rigsy is fairly helpful, especially after he’s let in on the TARDIS.

Later, the 2-D aliens grab a policewoman and drag her into the rug. All that’s left is a mural that’s really her nervous system. The Doctor sees the aliens are “dissecting” and “studying” people, trying to understand us 3-D humans.

As the painters try to cover those figures in the tunnel, the Doctor also suspects those painted figures used to be people. Clara tells the painters to leave, using her psychic paper to pass herself off as a Health and Safety inspector. It doesn’t work for Fenton (Christopher Fairbank), the grouchiest member of the crew. Once the figures start turning around, the crew leaves.  They still want to know who she is, and she tells them she’s the only chance they have to survive (which is what the Doctor would say if he were there). He asks “Dr. Clara” what she’d do next. She says lying to them, giving them hope, would be what he’d do.

Trying to communicate with the aliens, and ask them if they realize what they’re doing, doesn’t work, either. They evolve to 3-D by using the skins of the people they killed, and are sucking energy away from the TARDIS. He tries to help out with a Toodis, which changes objects from two to three dimensions. That works until the aliens can do the same. There’s a way the aliens can be beaten, but the Doctor says the TARDIS doesn’t have enough energy to do it.

Thanks to Fenton, the TARDIS is dropped on train tracks, and a train is coming. Clara tells the Doctor to move the TARDIS like “Addams Family”. That means he has to be like Thing, and move it with his hand. It’s an unforgettable sight, but it winds up on the edge of a track. He is forced to send the TARDIS into siege mode, which means the ship is sealed.

So, Clara is on her own. She has to come up with something to stop the 2-D aliens from flattening all of London. They find their way to a tunnel, and another train is coming. She uses the sonic screwdriver to stop it, then thinks how they can ram the train through those aliens. Rigsy decides to drive it, but Clara uses her headband to lock down the accelerator. It doesn’t quite work as the train winds up on the wall.  She also finds a strange cube which she suspects is the TARDIS.

The Doctor is still stuck, but is worried he’s about to take his last breath. He says, “Clara, you were good and a mighty fine Doctor”. This may raise hopes that the Doctor will regenerate into a woman someday. At least Jenna Coleman proves it can be done.

Clara comes up with an idea, and it involves Rigsy making a special painting. The monsters see the painting of a door, and expel energy on it. However, it’s really a way to recharge the TARDIS. Once it’s fully powered, the Doctor says it doesn’t matter why the aliens did what they did, they were monsters, and he’s the guy who kills them. “I am the Doctor,” he declares, “and I name you the Boneless.”

So, the day is saved, but even the Doctor knows it came at a big cost. He’s rather upset at Fenton saying that those who died were just “community payback scumbags”.  He is pleased with Rigsy for making a painting that saved everyone. Clara knows that the Doctor said she was good, but suspects he may have been delirious. She still wants some praise from him. He says, “you were an exceptional Doctor, Clara. Goodness had nothing to do with it.”

Why the damning with faint praise? It could be frustration he was trapped inside the TARDIS. It could be that people died, and that those aliens had to be killed. Deep down, he must have been impressed by what Clara did. It’s likely her grace under pressure may be related to her making that tough choice two weeks ago in “Kill the Moon”. He still should have complimented her.

Meanwhile, Missy (Michelle Gomez) is back, looking at Clara on her evil iPad. She claims that she’s chosen well, but for what? It’s still not clear what she’s got planned, and it won’t be revealed until two weeks from now.

Next week:  London has been turned into a massive forest, but why?