“I am a famous liar,” boasts Johnny, the swaggeringly vulnerable teen protagonist of Adam Cass’s fascinating one-man play I Love You, Bro. He is, he hints, a bigger liar than Shakespeare himself.

Certainly Johnny sees himself as a tragic hero, or perhaps heroine. He might be only 14, he tells us, but that doesn’t mean his feelings are childish; after all, Juliet was 14 when her love for Romeo drove her to kill herself. And you don’t doubt for a moment the truth of Johnny’s emotions, although he reveals a bizarre story of cyber-deception that can have few parallels.

I Love You, Bro tells the story of extreme obsession: Johnny’s crush on the popular but slow-witted schoolboy Mark. Truth and fiction are entwined from the very conception of this intriguing one-man show, which is about much more than the shadowy perils of cyberspace and teen sexuality.

This play was an award-winning hit of the 2007 Melbourne Fringe and garnered a swag of rave reviews at the Edinburgh Festival. Its return season at the Malthouse allows those of us who missed it the first time round to see what the fuss is about.

Perhaps the strangest thing about it is that it is closely based on a true story about a 14-year-old Manchester boy, who was convicted of inciting his own murder by his best friend. Although the actual case is even crueller and more sad than the story presented here with such actorly élan by Ash Flanders, Cass sticks pretty closely to the reported facts.

That this is more than a piece of documentary theatre is largely a function of Cass’s stylised writing and Flanders’s brave performance, which is elegantly directed by Yvonne Virsik on a bare, raised stage with minimal lighting. Johnny’s invented characters seem to possess him: he claims that they have lives of their own, and that while he is pretending to be the different characters, he believes in them totally. His behaviour raises profound questions about the nature of identity and the essential amorality of human imagination.

Cass’s language, a motley vernacular reminiscent of Stephen Berkoff’s argot of Shakespearean language and cockney slang, is a striking fusion of chatroom slang and poetic invention. As the monologue unfolds, Johnny's cockiness and aggression become more and more infused with bewilderment and loss, until the show is finally about the longing for emotional contact that drives him to such furious and destructive invention.

It’s a dense text, and the decision to perform it with a midlands accent means that for the five minutes or so, until the ear adjusts, it’s sometimes hard to catch its complexities. The play doesn't escape the odd feeling of longueur; just after half way, once everything has been revealed and all that remains is a nightmare of repetition, it loses dramatic energy. But this picks up swiftly. It’s certainly a show that demands attention; but it also rewards it.

Poupée, a short dance work choreographed by Trudy Radburn at fortyfivedownstairs, is a light but sharp-edged exploration of feminine identity. The two dancers, Sally Smith and Trudy Radburn, first appear as four legs emerging from a huge mass of white tulle: above the tulle arms pop up and vanish, like puppet birds casing the landscape.

The bird motif returns often through Poupée, which moves lightly through different phases that explore various rites of feminine passage - birth, childhood, awakening sexuality, marriage, loneliness. At times the bird gestures throw human agency into serious question, as they recall territorial or mating behaviour, trapped in the shapes of instinct; sometimes they are simply joyous or absurd; sometimes they celebrate our closeness to the natural world, and and others seem sinisterly reductive.

It's funny, moving and multifaceted performance. Like last year's enchanting Care Instructions, it explores the dilemmas of gender with grace and wit and lightness. The dance is rich with constant surprise, of which perhaps the coup is the appearance (apparently from nowhere) of the pianist and composer, Madeleine Flynn.

As its name indicates, the other major motif of the dance is that of the doll, the plaything that is all outer appearance and has no inner life. The dancers are, at different times, warring aspects of the self, mirror images, enemies, rivals. Ultimately, they are doleful and exhausted, their desire for friendship or communication thwarted by the feminine selves that hide them from each other (or themselves). So for all the frou frou of Emily Barrie's simple but lush design, it's ultimately a rather bleak show. But no less beautiful for that.

Part of this review was in Monday's Australian.

Pictures from top: Ash Flanders in I Love You, Bro; Trudy Radburn in Poupée.

I Love You, Bro, by Adam Cass, directed by Yvonne Virsik. Design by Jason Lehane, music by Nick Wollan. With Ash Flanders. Three to a Room and Malthouse Theatre @ the Tower Theatre, until February 28.

Poupée, choreographed by Trudy Radburn. Design by Emily Barrie, lighting design by Efterpi Soropos. Danced by Trudy Radburn and Sally Smith. Fortyfive downstairs. Closed.