“The Eaters of Light” is episode ten of season ten of the new Doctor Who.
In the previous episode, “Empress of Mars”, the TARDIS went back to Earth by itself, taking Nardole with it and leaving the Doctor and Bill stranded in 19th century Mars. In order to fix it, Nardole released Missy from the Vault – somewhere she was supposed to be kept for a thousand years. Which are presumably not up yet. What this will mean in the long term is open to question, but the Doctor did not seem happy.
Meanwhile, this episode opens in the present, at the Devil’s Cairn in Scotland. A young girl is running up the hill, accompanied by her older brother. She says she wants to hear the music from inside the hill. Her brother says that there are ghosts in the hill, who will come out of the hill and eat the listener. The girl doesn’t seem so impressed, then hears music coming from the hill. A crow flies up and perches on one of the stones, croaking ‘Doc-tor.’ The stone itself has a crude representation of the TARDIS on it.
The TARDIS itself arrives in Aberdeen in the second century AD (Nardole is not happy). The reason is that Bill and Doctor are arguing about what happened to the fabled, and vanished, Ninth Legion. The Doctor says that they were annihilated in battle. Bill disagrees – she’s a big fan of the Ninth Legion. Bill goes to check the river to find the legion she insists is there. The Doctor goes and looks for the battlefield. Splitting up. Never a good idea. Don’t they watch horror films?
Bill finds a woman with blue markings on her face (a Pict?) by a fire. The woman is not friendly and chases her with weapons drawn and something was also watching. Bill then falls down a hole.
Nardole and the Doctor find the stone cairn from earlier by the looks of it, and Nardole hears a talking crow. Which starts a conversation between him and the Doctor regarding talking crows, and why they don’t talk in the future (they’re sulking).
Bill finds a Roman soldier in the hole and wishes she could speak to him in Latin. He understands her perfectly, saying that she’s speaking Latin. Bill presumably hasn’t had the TARDIS’s translation feature explained to her; she had thought everyone in space spoke English.
The Doctor and Nardole have also found a legionnaire. Only theirs is dead – dead from a complete lack of sunlight. Not, as Nardole suggests, death by Scotland, because it happened far too quickly. The Doctor says it’s alien work. They then find most of the rest of the Ninth Legion, all dead. And some Picts as equally unfriendly as the one Bill found. Bill’s legionnaire, as they have climbed out of the hole, says that they were attacked by a monster. Then he is too, leaving Bill to find the rest of the, quite young, survivors.
The Doctor and Nardole have been taken by some (extremely Scottish, which the Picts weren’t) Pictish children, who talk about a gate, and one of them is the gatekeeper, who claims that she killed all the Romans. The Doctor is not convinced. Or impressed. There is a gate though, to somewhere else, in the cairn. On the other side are the Eaters of Light, and one of them is the monster which destroyed the Ninth Legion. Which will destroy the entire world. And then perhaps everything.
More humour with Nardole and Bill having a discussion with her legionnaires about liking men and women. There’s also a bit of the recurring problem where music drowns out the speaking.