Despite an wieldy, unappealing title that threatens to prove longer than the play itself, American author-actor Keith Stevenson's 70-minute tragicomedy turns out to be a delightful, if somewhat slight, surprise.

Set in a grubby West Virginia motel room - Simon Scullion's gruesomely convincing design transforms the entire Trafalgar Studio Two into a rundown amalgam of filthy, mismatched soft furnishings, scuffed woodwork and hideous light fittings - it at first appears as though we have been plunged deep into the dysfunctional backwoods world of an early Tracy Letts play. This impression is further reinforced by burly, bearded man-bear JD greeting a complete stranger at the door by clapping his hand over his mouth and dragging him roughly inside.

However, what subsequently follows completely defies expectations: Stevenson has created a depiction of almost unfathomable kindness and sweetness in the face of considerable odds, and it is as charming, whimsical and flat-out hilarious as it is foul-mouthed and edgy, as ingenious as it is crude. The acting is superb.

It is a challenge to describe the piece in any further detail without spoiling the many surprises, but suffice it to say that none of the male characters are quite as they appear to be. We may not be sure for a long time if JD is delusional or for real but he is a truly original comic creation, winningly played by Stevenson himself, endlessly expounding his very personal take on dealing with his fellow man, all the while necking vodka and making unhygienic looking fish sandwiches.

Similarly off-the-wall is thuggish scrounger Tommy (brilliant Alex Ferns, all explosive energy, pent-up aggression and mad eyes) who unexpectedly possesses the soul of a poet, and Flip (Michael Wade, wonderfully creepy) the elderly redneck landlord who turns out to have a lot more of a live-and-let-live attitude than you might initially think. If the sole woman -hysterical crystal meth addict Marlene- feels clichéd in a way that the male characters so refreshingly do not, Melanie Gray plays her with impressive energy and commitment. As the appalled outsider who suddenly finds himself in the midst of this band of misfits, Robert Moloney accurately charts a journey from incredulity through fear to a kind of grudging admiration. One of the biggest strengths of Harry Burton's well-judged production is the realisation that none of the actors are actively playing for laughs, not even Gray in the least developed role: they don't need to, Stevenson's crazy inventiveness does much of the work for them.

There is a tiny but effective coup de theatre in the final moments that will resonate in different ways for different people, largely depending on one's perception of the central character. The dialogue sparkles with a potty-mouthed wit. Stevenson has written a sequel which is unsurprising given the brevity of what's on offer here, and in all honesty this does feel a little slight for an entire evening's entertainment. However, it is a lot of fun, and has a brain as big as its heart. Stevenson is a major talent and it will be fascinating to see what he comes up with next. You probably won't want to go out for tuna sandwiches afterwards though.

Out There on Fried Meat Ridge Rd. runs at Trafalgar Studios until 3 June.