He’d brought several plays to the movie screen, some adaptations critically welcomed (Long Day’s Journey into Night, The Fugitive Kind, The Offence) and others meeting mixed receptions (The Sea Gull, Last of the Mobile Hot-Shots, Child’s Play). But the question on many minds following back-to-back triumphs with movie originals Dog Day Afternoon and Network was: what kind of film would director Sidney Lumet make of the blazingly theatrical and quite controversial Peter Shaffer psychological sparring match Equus (1977)? The cinematic answer arrived 38 years ago today; it divided critics, who debated whether the literalism of the screen diminished the mysterious poetry derived from the play’s stagecraft. But the impact of the shocking tale of a teenage stable boy undergoing intensive analysis by a burned-out psychiatrist after the youth blinds six horses stayed strong for The New York Times’ Vincent Canby, who called the movie “the most interesting, most serious appraisal of psychiatry that we've ever had in a commercial film.” Lumet’s stage-to-screen adaptations always possessed two surefire attributes: respect, if not necessarily slavish adaptation to the original text (Shaffer adapted his play here) and actors atop their game. Spearheading the Canby-lauded psychiatry appraisal are two of the best: Richard Burton as the repressed shrink longing for a breakthrough of his own and Peter Firth as his patient whose liberating fantasies, fueled by religious fervor and sexual awakening, appeal to the doctor even as he must untangle and, crucially, suppress them. Both had done the play on Broadway, Firth originating his role and Burton coming in as a limited-engagement replacement, reigniting the play to sellout capacity and later honored with a Special Achievement Tony® Award. For the movie, each won Golden Globe Awards and earned Oscar® nominations for their extraordinary work. Lumet didn’t stop there: the ensemble also included Jenny Agutter as a horsewoman who connects with the troubled boy, Joan Plowright and Colin Blakely as the young man’s parents, Eileen Atkins as the doctor’s confidante and Harry Andrews as the distraught stable owner. Executed with characteristic thoughtfulness and commitment to the material, Equus is fascinating to watch. On Twilight Time hi-def Blu-ray, two great Bonus Features add to the experience: a marvelous Julie Kirgo/Nick Redman Audio Commentary, and the feature film documentary In from the Cold: The World of Richard Burton (1988), Tony Palmer’s hypnotic portrait of the uniquely gifted actor which uses footage from Equus as a sort of framing device. Lumet would make two more stage-to-screen adaptations, The Wiz (1978) and Deathtrap (1982), both of which fell into the “mixed reception” category. Those are horses of another color.