Peter Davison

The Doctor

Sarah Sutton

Nyssa

Janet Fielding

Tegan Jovanka

Mark Strickson

Vislor Turlough

Nicholas Courtney

Brigadier Alistair Gordon Lethbridge-Stewart

Valentine Dyall

The Black Guardian

David Collings

Mawdryn

Angus MacKay

Headmaster

Stephen Garlick

Ibbotson