Tranter

Tranter was a Space Security Service officer in command of Station 7.

Biography
In his youth, Tranter fought the Daleks, and hated them so much he adopted the slogan "The only good Dalek is a dead Dalek." While first assigned to Station 7 as a junior officer, Tranter spoke out against Professor Weston's proposal to genetically modify Daleks into pacifists. He was reassigned to the front lines for his hot-headedness, where he earned numerous military awards.

Tranter was reported lost in battle when he was captured by the Daleks. They tortured him for information on Station 7. They also gave him false memories of his time in prison and escape, a specific behaviour pattern and an ocular implant. The Daleks used Tranter as an agent, controlling his thoughts, accessing what he saw through the ocular implant. They tracked his location through a transmitter.

After he was permitted to escape and found by his comrades, Tranter was released from active combat and offered any desk job he wanted. Under Dalek influence, he chose command of Station 7. Weston jettisoned his laboratory onto the planet below, fearing that Tranter had come back specifically to stop his research.

Some time later, the Eleventh Doctor and Amy Pond came to Station 7 and were brought to Commander Tranter by Jay. As their psychic paper said they were inspectors- and the Doctor mentioned his previous association with Bret Vyon and Sara Kingdom (The Daleks' Master Plan)-, Tranter explained the research carried out in the Station. One project, headed by Kustler, involved the conversion of Daleks for remote control by humans. He objected to this, as did the Doctor. Soon after, the Daleks attacked Station 7. Tranter ordered the conversion and re-armament of Daleks to use against the attackers. The converted Daleks turned on them and they were forced to flee (as Weston had), leaving Station 7 to be destroyed by the Daleks.

On the planet below, Tranter and the Doctor found Weston and the result of his research: a pacified Dalek. However they learned from Weston that Jay and Amy were tracking them down with a 'converted' Dalek and that other Daleks were close. Once Amy and Jay arrived, the Dalek was stopped from exterminating the pacified Dalek, and the mutant trapped in a container. Its casing was prepared for the pacified Dalek to help them escape, while a countdown was set for the laboratory's reactor to explode.

As they made their way to safety, they were blocked. Tranter volunteered to go with Jay to the laboratory to open hatches for a different route. Once there, Jay realised Tranter had purposely put the unmodified Dalek back in its casing. The Doctor intervened and revealed Tranter as a Dalek agent, after which he cut off the Daleks' control.

Again himself, Tranter deactivated the reactor's safety mechanism while the pacified Dalek re-activated the countdown, leaving neither time to escape. Tranter's sacrifice helped defeat the Daleks and let the others escape, earning his redemption. (GN: The Only Good Dalek)

Other information
Tranter knew of Bret Vyon and Sara Kingdom by reputation at least, regarding the Doctor's friendship with them as proof of his impressive credentials.

Behind the scenes
He is clearly named after Torchwood's then-executive producer Jane Tranter, who was also responsible for bringing the rights to Doctor Who back on screen while controller of drama commissioning for the BBC.