Bold Girls, Eclipse Theatre Company.

Lop off the last 15 minutes of Rona Munro’s Bold Girls, receiving its U.S. premiere at Eclipse Theatre, and you’d have a terrific show. Deftly acerbic and bluntly honest in her depiction of contemporary Belfast, Munro has created four vivid and distinct characters whose grim secrets and foibles rivet one’s attention: Nora, the brave, wise survivor of an abusive marriage; Cassie, her sarcastic, self-destructive daughter; Marie, their saintly widowed neighbor; and Deidre, the kleptomaniac urchin who comes into their lives, wreaking havoc with her revelations.

Munro is thoroughly engaging when she concentrates on the relationships between these characters. Their conversations and arguments with one another and their monologues reveal the devastating humor and unblinking misery of truth. And in Eclipse’s grittily realistic and superbly acted production, Munro’s play has all the immediacy and intensity of a work in the heyday of Chicago storefront theater.

But in the final quarter of the play Munro overreaches, coming up with so many contrived plot twists and unsurprising surprises that Bold Girls turns from gripping drama to implausible melodrama: as I count them, there are at least four life-shattering facts disclosed in a span of about 20 minutes. Bold Girls hurtles over the cliffs of logic, and even the bold quartet of Eclipse actors can’t rescue it.