Tyssan

Tyssan was a starship engineer who served with Earth's deep space fleet.

Biography
In 4498, Tyssan was captured by the Daleks and imprisoned on one of their spaceships until fifty slaves including himself were taken down to Skaro to clear out a mining area where the Daleks had been excavating. Tyssan managed to escape two years after his capture.

He and all the other slaves were informed by the Daleks that every time one of them escaped, five others would be exterminated in their place. Tyssan avoided recapture and, while exploring Skaro, startled Romana II, whom he had watched, after she and the Fourth Doctor's arrival on Skaro.

After the Doctor bargained for the release of the slaves from the Daleks, Tyssan led their attack on the Movellans' ship. After their victory, Tyssan led a charge against a group of Daleks sent to destroy the Movellan ship they had taken over. Tyssan remained in charge of the Movellans' craft following the second attack and assisted in transporting a cryogenically frozen Davros back to human space. (TV: Destiny of the Daleks)

Legacy
Tyssan's name was listed on Davros's cryogenic chamber, which the Tenth Doctor recognised. (AUDIO: The Dalek Defence)

Behind the scenes

 * Actor Tim Barlow was profoundly deaf at the time of filming, but was able to lip-read. Tyssan, however, was not shown to be deaf as well; the first acknowledged deaf character in televised Doctor Who was Cass in Under the Lake, played by deaf actor Sophie Stone.