Fesk

Fesk was a Sontaran General of the Eighth Battle Fleet. He kidnapped Ollistra in order to use her as a bargaining chip to both the Daleks and the Time Lords to allow them into the Last Great Time War. He tricked the Dalek Time Strategist in to meeting him and took the Strategist prisoner. (AUDIO: The Eternity Cage)

Behind the scenes
Fesk is played by Dan Starkey in the audio, but the image used in the cover is of Sontaran actor Christopher Ryan.