Omega, an ancient Time Lord made of pure anti-matter, once defeated by the Doctor, is plotting to cross over into this dimension by bonding with the Doctor. Meanwhile, the disappearance of a man in Amsterdam piques the curiosity of his cousin, Tegan, who previously left the Doctor at Heathrow Airport and now finds herself at Omega's mercy. Fearing total destruction from the collision of matter and antimatter, the Time Lords recall the Doctor to Gallifrey to undertake the only viable solution: executing him!
Peter Davison
as The Doctor
Sarah Sutton
as Nyssa
Janet Fielding
as Tegan Jovanka
Leonard Sachs
as President Borusa
Elspet Gray
as Chancellor Thalia
Michael Gough
as Councillor Hedin
Paul Jerricho
as The Castellan
Max Harvey
as Cardinal Zorac
Colin Baker
as Commander Maxil
Ian Collier
as Omega/The Renegade
Neil Daglish
as Damon
John D. Collins
as Talor
