Professional ratings
Review scores
Source	Rating
Rotten Tomatoes (Tomatometer)	100%
Rotten Tomatoes (Average Score)	8.22
The A.V. Club	B+
Entertainment Weekly	B+
SFX Magazine
TV Fanatic
IGN	8.1
New York Magazine
Radio Times
Daily Mirror

"Oxygen" is the fifth episode of the tenth series of the British science fiction television series Doctor Who. It is written by Jamie Mathieson and was broadcast on 13 May 2017 on BBC One. "Oxygen" received mostly positive reviews from critics, most commenting on the overlying themes of the episode and the aspect of capitalism.

The Doctor (Peter Capaldi), Bill Potts (Pearl Mackie) and Nardole (Matt Lucas) investigate a space station after receiving a distress call sent by them, but find that the station is infested with a crew of walking dead. The trio need to base their plans on how much oxygen they have left, when they find themselves in a situation of no hope.

The Doctor, Bill and an angry Nardole travel in the TARDIS to follow a distress call to a deep-space mining station. When the TARDIS is jettisoned by the station's computers, the trio are forced to wear "smartsuits", robotic spacesuits capable of independent operation tied to the station. The suits are also the only source of oxygen, as the mining company does not provide an oxygen atmosphere inside the station, and every activity is measured in breaths. The surviving crew warn them that some suits have received instructions to "deactivate" their "organic components", killing the wearer via an electrical discharge but remaining autonomous. This signal can be carried by touch, which has caused most of the crew to be turned into zombies, enslaved to the suits' programming. The Doctor and the others plan to walk outside the station to an uncompleted portion not updated in the computer systems to hide. Bill's suit malfunctions during depressurisation and forces her to remove her helmet. To save her, the Doctor gives her his helmet as they spacewalk. He survives the vacuum of space, but has gone blind from the ordeal.

The computer discovers their location, but as they flee, Bill's suit again malfunctions and will not move. The Doctor leaves her behind, assuring her she will not die. She is, however, electrocuted when they touch her. The Doctor reveals the limit of breaths is an algorithm to stop people "wasting" oxygen, part of the company's automated profit-making system; killing the wearers was just the logical endpoint of corporate profit over human life. He hacks the station's systems to cause the station to self-destruct if they are killed, and convinces the others this is a "good death" and revenge against the corporation. The computers recognise this threat and recalculates the suits' programming, and the zombies turn over their oxygen supplies to the survivors. The Doctor then revives Bill, knowing that her malfunctioning suit did not have enough power to lethally shock her.

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