The Doctor takes Ace on an initiative test to a strange Victorian old house where she is forced to confront her darkest fears.
| Actor | Role |
|---|---|
 Sylvester McCoyThe Doctor | The Doctor |
 Sophie AldredAce | Ace |
 Ian HoggJosiah Samuel Smith | Josiah Samuel Smith |
 Katharine SchlesingerGwendoline | Gwendoline |
| CCarl ForgioneNimrod | Nimrod |
 Sharon DuceControl | Control |
 Frank WindsorInsp Mackenzie | Insp Mackenzie |
 Sylvia SymsMrs Pritchard | Mrs Pritchard |
 John NettletonRev Ernest Matthews | Rev Ernest Matthews |
 Michael CochraneRedvers Fenn-Cooper | Redvers Fenn-Cooper |
 John HallamLight | Light |
| BBrenda KempnerMrs Grose | Mrs Grose |