“Risk to life: absolute.” Injured and stranded in the wilds of a far-flung galaxy, The Doctor, Yaz, Graham, and Ryan must band together with a group of strangers to survive against one of the universe’s most deadly — and unusual — creatures.
Guest starring Suzanne Packer, Ben Bailey Smith, Brett Goldstein, and Lois Chimimba. Written by Chris Chibnall. Directed by Jennifer Perrott.
While scavenging on an alien junkyard planet, the Doctor, Graham, Yasmin, and Ryan are caught in a sonic mine’s detonation. They wake aboard the Tsuranga, an automated ship traveling to a medical space-station. Exploring the ship, the Doctor meets some of the patients being transported – Eve Cicero, a renowned general; her brother Durkas; Eve’s synth robot partner Ronan; and Yoss, a pregnant man. After gaining access to the ship’s systems, the Doctor, alongside head nurse Astos, notice something heading for the ship. They realize it is an alien entity, which gains access to the ship and starts damaging its escape pods. Astos becomes trapped in one that he is inspecting and dies when the pod is jettisoned into space and explodes.
Helped by Mabli, Astos‘ colleague, the Doctor learns that the entity is a Pting, a creature that eats non-organic material and is classed as highly dangerous. Learning that the ship will be remotely detonated if the space-station detects the creature aboard, the Doctor works to prevent this from happening. While Yasmin and Ronan defend the ship’s power source from the Pting, Ryan and Graham offer to help Mabli with Yoss as he enters labor. Meanwhile, the Doctor, Eve and Durkas focus on gaining manual control of the ship. During this time, the Doctor learns that Eve has a critical heart condition that could kill her if she interfaces with the ship. Despite this, Eve sacrifices herself to protect everyone aboard the ship by keeping it safe, before Durkas assumes control in her place.
The Doctor suddenly deduces that the Pting was attracted to the ship looking for energy sources, its true food source. With this knowledge, she returns to the ship’s power source where she rationalizes it has a built-in failsafe bomb. Removing it, she primes the device and feeds it to the Pting, giving it ample energy before she jettisons it into space. Durkas safely brings the Tsuranga to the space station, while Ryan and Graham help Yoss give birth successfully. Before leaving to recover her TARDIS with the others, the Doctor joins Mabli and the patients in honoring the death of Eve for her courage in protecting them.