Ruth Matheson

Ruth Matheson was a captain who was in charge of the Vault.

Biography
Matheson gave Charlie Sato a tour of the Vault when first became its warrant officer. In the Vault they came across four objects: An army jacket, a painting, crystal and a wax cylinder, which bore a significance. Each was used in one of the Doctor's many adventures. (AUDIO: Tales from the Vault)

Matheson and Sato were tasked with guarding the Master. This task was unsuccessful, as the Master managed to trick the duo and escaped in his TARDIS. (AUDIO: Mastermind)

After the escape of the Master, Matheson was held at UNIT's private residence for comprimised UNIT soldiers. She and Sato were later brought back into active service by Mike Yates, who needed her help to investigate what had happened to the Vault since they left. (AUDIO: The Screaming Skull)