Peter Shaffer’s 1973 psychological drama examines Alan Strang, a tortured teenager whose erotic, quasi-religious fascination with horses ends in violence. Currently enjoying a successful West End revival starring Harry Potter’s Daniel Radcliffe (whose nude scenes have caused a lucrative stir), the play is long and overblown but can exert an eerie power in the right production. In Joe Stead’s simple, reverent staging for the Actors Workshop Theatre, performed in a tiny space, the cast works wonders. Mellifluous Brian Parry is smooth but authoritative as Strang’s therapist. And smoldering newcomer Peter Oyloe gives the boy a solemn, sullenly seductive air that perfectly suits Shaffer’s theme, the intermingling of sex and violence with the sacred. –Zac Thompson a Through 4/22: Fri-Sat 8 PM, Sun 3 PM, Actors Workshop Theatre, 1044 W. Bryn Mawr, 773-728-7529, $20-$25.