Ali McDowall is very much the man of the moment. His play Brilliant Adventures opened to massive acclaim at the Royal Exchange in May, his next, Talk Show, wowed Open Court audiences in London, and now, in spite of its short run, Live Theatre Newcastle's production of Captain Amazing has, rightly, become the kill-to-get-a-ticket toast of the Fringe at Northern Stage.

The one-hander deftly sketches several years in the life of a couple from meeting to, well, I won't spoiler it for you. The story is told in flashbacks of dialogues, both from reality and from the adventures of 'Captain Amazing' – the superhero who Mark is in his imagination.

There are two main advantages to this choice of form (compared with staging all the "real" stuff "properly". Bleugh). Firstly, it give us the opportunity to witness a virtuoso performance by Mark Weinman, in Clive Judd's smartly directed production. Secondly, it gives McDowall the opportunity to be very funny with a series of increasingly off-the-wall riffs on how superheroes behave in their downtime. As a result, this quotidian, but ultimately heart-breaking, story leaps beyond the bounds of dull reality and takes on a fully muscular life of its own.

But for all the acute intelligence and humanity of McDowall's script it is possibly Weinman's performance which really makes the show. Pitching Mark and his titular alter-ego as a diffident gruff Londoner-of-few-words – imagine Ray Winstone in a rom-com – the extent to which he changes his voice, facial expression and physicality to embody Mark's partner, young daughter and Captain Amazing's nemisis Evil Man – not to mention a supporting cast of other superheroes, Batman ("not a superhero" but "a billionaire with a leather fetish") and a vain estate agent – is completely captivating. There's a charming throwaway brilliance to it all.

This short Edinburgh run has now finished, but if Live Theatre have any sense (and word is that they do), we can confidently expect a revival and tour as soon as humanly possible.

- Andrew Haydon