Conor McPherson’s 1994 one-act monologue is delivered by a petty criminal whose attempt to scare a local merchant for a Dublin crime boss spins wildly, violently out of control. The playwright clearly wants us to both pity and scorn this foolish man, who nearly pays for his bad luck with his life, so The Good Thief depends for its power on an actor able to convey all sides of the protagonist: his anger and remorse, his good heart and heartless sense of humor. Michael Patrick Thornton, making a comeback after life-threatening multiple strokes and years of physical therapy, plays McPherson’s unnamed storyteller with remarkable subtlety, never overemphasizing the violence, never punching the many comic lines. Thornton still needs a walker to move about the stage and seems to have only partial use of his hands, but that only makes his stage work all the more remarkable–and moving. Through 7/1: Thu-Fri 8 PM, Sat 3 and 8 PM, Gift Theatre Company, 4802 N. Milwaukee, 773-283-7071, $15-$25.