Mastermind (audio drama)

Mastermind is an audio drama based on the long-running British science fiction television series "Doctor Who". This audio drama was produced by Big Finish Productions.
Plot.
The Vault – an archive of alien artefacts securely stored deep beneath the Angel of the North.
<br>
There's also a prisoner in the Vault. An extraterrestrial known as the Master. He has been on Earth for some time, but now he's under lock and key.
<br>
This is his story.
<br>
Or, as Captain Ruth Matheson and Warrant Officer Charlie Sato discover… perhaps it is theirs.