When not in an (unflattering / fetching - delete as appropriate) wig and tartan playing a Village Leader and warrior, Stephen Cranford plays the Time Lord official 'The Covellitor'
Charged with ensuring the test goes to plan, he becomes increasingly nervous about the turn of events. Finally, as the pilot of the second Tardis, he is forced to take evasive manoeuvres to try to keep the team alive after they are attacked by the twisted character Auriga.
After a crash-landing in wasteland he attempts to keep the remaining crew alive, with limited success. Reaching the complex housing the time-weapon he leads the depleted and rapidly ageing rescue party try to rescue the Doctor -and ends up doing more than he expected as events unfold.