Eugene O’Neill’s autobiographical “play of old sorrow” has certainly received grander stagings than this one in a small, boxy storefront. But seldom has the suffocating atmosphere of the Tyrone summer home been so convincingly evoked: in Gift Theatre’s nearly four-hour production, directed by Michael Patrick Thornton, every glance and tic is freighted with dread. “She’s watching us watching her,” observes alcoholic Jamie Tyrone of his morphine-addicted mother, Mary (a splendid Alexandra Main), as she slides into a self-induced fog, spidery fingers plucking at her dress. Gary Wingert peels back the layers of parsimonious patriarch James Tyrone to reveal his paralyzing terror of poverty and soul-killing disappointment in life, and Brendan Donaldson and John Kelly Connolly as his sons, Edmund and Jamie, make the last act emotionally devastating. Through 10/15: Thu-Sat 7:30 PM, Sun 3 PM, Gift Theatre Company, 4802 N. Milwaukee, 773-283-7071, $15-$25.