Mark O'Rowe's inter-locking monologue play of two hoodlums converging in the same hilarious story of Dublin low-life, violence and sexual braggadocio, was initially performed by two actors.

Re-visiting the play after 12 years, the author directs an expressive, muscular Tom Vaughan-Lawlor in both parts, as if he were playing different manifestations of the same character chasing the one tail, each other.

Kenneth Tynan once said of Brendan Behan that he wrote as if drunk with words, his language out on a spree. O'Rowe, like Enda Walsh (whose roller-coaster Disco Pigs is the nearest to Howie in style), is intoxicated with words, and they come at you with the lip-smacking relish and the whooping vulgarity indeed of Behan, or of James Joyce, or Flann O'Brien.

Both Howie Lee and his namesake Rookie are careering through pubs, wild nights with fat girls, one of them called Avalanche ("her widening nostril beckons and says, let's"), the 123 bus route, car chases and petty criminals. But there's a terrible savagery about it all, too, with the shocking death of a child darkening the first part and a vicious bust-up over a prized tropical fish electrifying the second.

Vaughan-Lawlor marks the division in a change of T-shirt, going from mauve to blue. O'Rowe's brilliant and entertaining text sits up in lights in the actor's technically perfect articulation and physical control, and the play shines like a rare jewel in a dung heap.

Howie the Rookie continues at Assemble Hall until 25 August (not 7)