Psychology students Sylvia, Helga and Tim are invited to the home of the renowned Professor Carnaby for a weekend seminar, but little suspect that they are in fact to be the guinea pigs in a terrifying real life experiment. Carnaby has been researching conditioned behaviour in criminals, and is determined to test his 'cure' on live human subjects. When the three undergraduates arrive at the house, they are tended to by the Professor's servant Boz, who is in reality a deranged psychopathic killer. Held in check only by his conditioning, Boz reverts to his homicidal tendencies at the sound of a bell. Dazzled by their host's charm and reputation, the students remain oblivious to the danger they are in, even after one of them seems to recognise a notorious escaped killer in another of the house staff. Inevitably, two of them quickly vanish and Sylvia must face the terrifying prospect that they were murdered. Investigating more closely, she soon realises that she is at the centre of Carnaby's bizarre and unethical experiments, but even then doesn't suspect the full extent of the danger she is in, or from where it might really stem.
WRITTEN BY: Brian Clemens
DIRECTED BY: Malcolm Taylor
PRODUCED BY: John Cooper
MAIN CAST: Joanna Pettet (Sylvia), Patrick Magee (Professor Carnaby), Max Wall (Kesselheim), Eric Flynn (Slattery), Don Henderson (Boz), Petra Markham (Helga), Peter Settelen (Tim)