An alien distress call draws the Doctor and Peri to Earth, 1985, where they uncover a Cyberman plot to change the course of history.
| Actor | Role |
|---|---|
 Colin BakerThe Doctor | The Doctor |
 Nicola BryantPeri Brown | Peri Brown |
 Maurice ColbourneLytton | Lytton |
 Brian GloverGriffiths | Griffiths |
 Terry MolloyRussell | Russell |
| JJames BeckettPayne | Payne |
 David BanksCyber Leader | Cyber Leader |
| MMichael KilgarriffCyber Controller | Cyber Controller |
 Faith BrownFlast | Flast |
 Sarah GreeneVarne | Varne |
 Michael AttwellBates | Bates |
| JJonathan DavidStratton | Stratton |
| BBrian OrrellCyber Lieutenant | Cyber Lieutenant |
| JJohn AinleyCyberman | Cyberman |
 Stephen ChurchettBill | Bill |
| SStephen WaleDavid | David |
| SSarah BergerRost | Rost |
| EEsther FreudThrest | Threst |