The Doctor, Amy and Rory land in the small Welsh village of Cwmtaff in 2020, instead of Rio de Janeiro which irks Amy who is “dressed for Rio” and feels cold. The Doctor notices a major mining operation nearthe village and proceeds to investigate with Amy. Before they set off Rory asks Amy to leave her engagement ring back so she won’t lose it and she gives it to him. Rory goes to leave the ring in the TARDIS while Amy follows the Doctor.
Amy and the Doctor discover that the mining operation is a project by Doctor Nasreen Chaudry and her assistant, Tony Mack, investigating the appearance of minerals that have not been seen for over 20 million years (which the Doctor had also noticed in the form of patches of blue grass). Meanwhile, Rory is mistaken for a police officer by local resident Ambrose Northover (Tony’s daughter), and her son Elliot, who explains that the dead are being removed from their graves, but there is no sign of disturbance on the surface, which could only mean the bodies are being taken from below. Creepy.
An earthquake hits the mining facility, causing parts of the ground to open. Tony falls into the cracks and Amy goes to help him but falls in as well. Nasreen is able to pull Tony free but something beneath the ground drags Amy under. In the aftermath, the Doctor explains that the minerals were a warning to keep away and that when they started drilling, the ground ‘fought back’. The Doctor realises that the ground has been bio-programmed to attack whenever it perceives a threat, which should be impossible as he remarks humans will not develop such technology for millenia. At that moment, an alarm goes off; the drill, having gone down 21 kilometres has breached into a network of underground catacombs, and three unknown entities are heading up. With only twelve minutes until the unknown attackers reach the surface, the Doctor orders the pair to take safety in the local church, where they meet up with Rory, Ambrose and Elliot. The Doctor (using a slingshot!!!!) discovers that the attackers have erected an energy barricade to prevent escape and turned day into night for their own benefit. In private, the Doctor tells Rory what has happened and promises to get Amy back.
The Doctor has the group barricade themselves in the church and sets up a network of cameras to let him know when the attackers arrive, but problems arise when Elliot leaves to collect headphones from his house, as the attackers- strange reptilian humanoids- have arrived and take him. Ambrose and Tony run out to try and rescue him, but another one of the creatures attacks, lashing Tony with a venomous forked tongue before being subdued and captured by the Doctor and Rory with a fire extinguisher. The Doctor deduces that these attackers are a new species of an old enemy; the Silurians. At that point, the energy barricade dissipates and daylight returns; the Doctor explains that the Silurians have retreated, as now both sides have hostages to bargain with.
The group imprison the captured Silurian in the church’s cellar and the Doctor goes to interrogate it. The prisoner, a female member of the warrior caste called Alaya, reluctantly explains that her tribe had hibernated beneath Cwmtaff for eons, but the drill was perceived as a threat to them and the warrior caste were reawakened to deal with the threat. The Doctor explains that the humans didn’t mean any harm, but Alaya aggressively snarls that the Silurians will not tolerate mankind (whom she derogatively refers to as “apes”) on what they still view as their planet. The Doctor tries to warn her that mankind will fight back if threatened, but she is confident of the Silurians’ victory over humanity.
The Doctor explains the Silurians’ history to the group and that he intends to go underground and negotiate with the Silurians, and tells them that Alaya must be kept safe if they are to bargain with them. Tony (who has a really nasty and icky situation going on on his neck because of Alaya’s venom) comments that they should be studying the creature by dissecting it, but the Doctor refuses, saying that if Alaya is harmed, the Silurians could view it as an act of war. The Doctor and Nasreen, who having studied the earth all her life wants to see it for herself, descend in the TARDIS, while the others speak to Alaya. They try to assure her they don’t mean any harm and that she will be kept safe, but she replies that they will kill her, triggering an unwinnable war between humans and Silurians. She also remarks that she knows who will kill her, even if they don’t.
Deep underground, Amy awakens strapped to an examining table. Next to her is Ambrose’s husband, Mo, who was taken earlier by the Silurians. He apologises, explaining that the Silurians intend to vivisect them, as a Silurian in scrubs advances on them with a scalpel. The Doctor and Nasreen arrive in the catacombs, the Doctor explaining that they are unlikely to find more than a dozen Silurians, but falls silent as they enter a cave and find an immense Silurian civilisation, stretching for miles underground before them…
And… we’ll see what happens this Saturday!
Trailer for next time and Screencaps