Complex sentence: Back at the Movellan space craft, two Movellans enter with a new prisoner, it's the man who has been following the Doctor and Romana; he identifies himself as Starship Engineer Tyssan, who was captured by the Daleks two years ago.
Split into simpler sentences: Back at the Movellan ship, two Movellans enter with a new prisoner, the man who has been following the Doctor and Romana. He identifies himself as Starship Engineer Tyssan, who was captured by the Daleks two years ago.