Maybe it was a case of opening-night jitters. Maybe the show needed a few more rehearsals, as recurrent flubbed lines seemed to indicate. Whatever, Frank Merle's intelligent, well-paced staging of Michael Gazzo's seminal 1955 drama--the first postwar Broadway play to deal with drug addiction--never achieved the tragic scope it should have. It wasn't for lack of talent. The production features such off-Loop heavy hitters as the usually rock-solid Jeremy Glickstein as the protagonist, a Korean war POW whose hospital-induced morphine habit nearly destroys his family and leaves him deeply in debt to three thuggish pushers. This is the most even, convincing work I've seen from Merle to date; still, his strong cast only fleetingly found the script's life-and-death stakes. But considering how they nailed the final few scenes, this show may simply need another week to dazzle. Through 7/16: Fri-Sat 8:30 PM, Sun 7 PM. Raven Theatre, 6157 N. Clark, 773-338-2177. $12-$15.