It's easy to go wrong by being too-over-the-top while playing a nasty character. Jim Viront avoided that trap when he played Uncle Tony in the splendid Bang and Clatter production of Griller. Making Eric Bogosian's lacerating language his own, Viront first seemed like a fairly harmless old fart, visiting a family he'd known for decades. But this Fourth of July cookout turned terrifyingly vicious, as Viront slowly revealed his character's true nature and haunted past. Twitching and slumping like Cosmo Kramer, Viront squeezed every gram of dark laughter out of his rage-filled rants and macho boasts ("I wake up hard and I go to bed hard!"). But when he launched into his final remembrance -- of his participation in a wartime atrocity -- he pinned us to our seat as if holding a bayonet to our gut.