Introducing David Callan, in his first case after being invalided out of the special services.
| Actor | Role |
|---|---|
 Edward WoodwardDavid Callan | David Callan |
 Joseph FürstSchneider | Schneider |
 Ronald RaddHunter | Hunter |
 Peter BowlesToby Meres | Toby Meres |
 Russell HunterLonely | Lonely |
 Francesca TuJenny | Jenny |
 Ivor DeanWaterman | Waterman |
 Helen FordMiss Brewis | Miss Brewis |
 Martin WyldeckDI Pollock | DI Pollock |
| JJohn ScarboroughDS Jones | DS Jones |
| JJudy ChampHunter's Secretary (voice) | Hunter's Secretary (voice) |