The arrival of a mysterious comet heralds impending danger from enemies both old and new. As Ace helps the Doctor defend Earth, she is confronted with a dangerous question..."Doctor Who?"
Sylvester McCoy
as The Doctor
Sophie Aldred
as Ace
Anton Diffring
as De Flores
Fiona Walker
as Lady Peinforte
Gerard Murphy
as Richard
Leslie French
as Mathematician
Dolores Gray
as Mrs Remington
David Banks
as Cyber Leader
Mark Hardy
as Cyber Lieutenant
Metin Yenal
as Karl
Courtney Pine
as Himself
Chris Chering
as Skinhead 1
