Peter Shaffer's dark, ambitious, profoundly strange hit from 1973 tells the story of a 17-year-old boy (Bobby Conte Thornton) who, for reasons nobody can fathom, decides to blind six horses with a metal spike. His therapist (Michael Shipley) sets out to discover why. Director Erin Gilley transfers the action from England to America and reduces the ensemble from 15 to six, but the fundamentals remain intact — Equus is still a disturbing and intellectually thrilling story about religious devotion, sexual perversion, and sudden violence. Thornton is a fantastic young actor, his cherubic face concealing a surprising amount of lust and rage, and his sex scene with Jill (Lili Weckler) is just as intense and unsettling as it should be. Shipley is less successful; he never seems fully comfortable with his dialogue, so the play fails to gain much momentum when he's around. As with other shows at Boxcar this season, the production design is totally worth the price of admission: Nick A. Olivero's wooden-plank set is the perfect complement to Krista Smith's haunting lighting design, and Marc Blinder creates a rich soundscape for the disorienting climax. The show may not always work as drama, but it's a fine spectacle all the same.