Vira
First Medtech Vira was a human placed in suspended animation on the Nerva Beacon. She was pair-bonded with Noah, the commander.
In 16087, Vira was woken from suspended animation after the arrival of the Fourth Doctor, Harry Sullivan and Sarah Jane Smith. She in turn woke Noah. The commander wanted to have the travellers killed as they put the genetic pool at risk, but Vira convinced him to let the council decide. She the continued to perform revivification on the other medtechs.
It soon became apparent that Noah was acting out of character. He had been infected by the Wirrn. Regaining control of his mind, he contacted Vira and warned her about he coming danger, telling her to leave the beacon. Noah then handed command over to Vira.
After he had fully metamorphosised into a Wirrn, Vira talked with him. He again told her to leave the beacon, but she refused to abandon her task. Vira helped the Doctor rig the transport ship attached to the beacon so that it provided power to a set up in the cryogenic chamber that prevented the Wirrn accessing the suspended humans.
On the Doctor's instructions, Vira abandoned the craft and headed back into the station. The Wirrn, led by Noah boarded. The craft then took off, leaving the beacon.
Noah contacted Nerva to say "Goodbye, Vira" before the transport ship exploded. She realised he had retained some humanity in the end had had deliberately led the Wirrn to their deaths.
Vira said goodbye to the Doctor, Harry and Sarah as they travelled down to Earth. She told them that life would soon return to Nerva as the others awoke and that she would attempt to see them return to the Earth. The Doctor threw her a jelly baby and she looked up to find them gone. (TV: The Ark in Space)
