Grief twists through this new dark, sparkling gem of a play written and directed by Ronan Marra for Signal Ensemble Theatre. Twentysomething Diane has fractured a hand and a foot in a motorcycle accident, so her alcoholic brother comes to stay with her, partly to escape his crumbling marriage to the competent Sarah. Playing Diane, the magnificently ferocious Georgann Charuhas has a Sarah Vowell-like sarcasm based almost entirely on intonation; and as Diane’s brother, Christopher Prentice conveys a dark humor that shines through his flickering facial expressions. Together they’re bitterly funny as they wade through the rising tide of misfortune that threatens to drown them. With breathtaking clarity, Melanie Keller captures the flashes of despair and joy experienced by the absent Sarah, seen entirely in flashbacks. In this cathartic production, all three characters learn to keep moving forward though their hearts are destroyed. Through 4/10: Thu-Sat 8 PM, Sun 3 PM. Breadline Theatre, 1802 W. Berenice, 773-347-1350. $10-$15.