Judge Hesther Saloman (Eileen Atkins) approaches morose psychiatrist Dr Martin Dysart (Richard Burton) with a request that he unravel the mind of troubled teenager Alan Strang (Peter Firth) and discover why the young man blinded six horses.
In the process, Dysart discerns the boy’s psyche and determines that the source of the boy’s obsession is his devout mother Dora (Joan Plowright).
She has allowed her son to believe in a convoluted set of religious values and he has consequently imagined the transference of extremely physical religious devotion to Jesus, to the spirit Equus as embodied in horses.
The boy’s outrage at his personal deity is finally triggered by his sexual inadequacy during a tryst with stable girl Jill Mason (Jenny Agutter).
Peter Shaffer’s prize-winning psychological play loses much of its emotional impact and imagination in the transfer from stage to screen.
Shaffer’s screenplay fuses religion, sex, mythology and madness into an incoherent narrative, and Sidney Lumet has perhaps injected too much realism into this story.
The performances, however, are excellent all around. Burton plays the psychiatrist with steady fortitude and Firth brings depth and persuasiveness to his role as the boy.