The Fringe is great for many things, but it's not especially kind to standup comedians. If you don't have a narrative, a powerpoint presentation or some kind of gimmick, you're likely to get overlooked. Hail Mary sets out to jump that chasm, to create a great show that consists of nothing but jokes.

Right from the start you know this is going to be surprising, as the pleasant and unimposing Bourke saunters onstage to the sound of Public Enemy's Fight The Power. And so it goes, with Bourke using her lilting Irish charm to disguise the harshness of her jokes: routines about the time she was so rude to AA Gill that she got fired; her desire to hunt and kill the users of Mumsnet; a loathing of young, male, 'edgy' comics. Bourke's comedy is savage in intent and surgical in execution.

She completely dominates the pace of the gig, in much the same style that Stewart Lee is famous for, modulating betwen bubbly banter and slow-paced whispers. The show eventually reaches the biggest obstacle for this kind of thing: the bit around the 40-minute mark when audiences start to flag. Bourke clears it easily using a game that invites the audience to rate some one liners. It's true to the spirit of her show and peps the audience up for her big finale, which is a scathing discussion of the arrogance of some American comedians.

The showmanship and razzmatazz of the Fringe can sometimes make you forget what you first loved about comedy: the simplicity of one person, one mic and a lot of jokes. Bourke goes in search of that original spirit of standup and reclaims it with style.

There are so many beautifully crafted turns of phrase in Mary Bourke's show that there really should be a massive queue jostling to get into this tiny, out-of-the way room.

As she notes at the top of the show, and the reason for the 'contrary' of the title, this isn't what comics usually do for a Fringe show. There's no catharsis, no sentimental journey or revelations, just pure stand-up. And she delivers.

She's performed on the circuit for more than a dozen years and the experience shows. Bourke's utterly composed on stage, performing with a relaxed delivery, and the soft sing-song of her Irish lilt contrasts nicely with her punchy and somewhat acerbic material.

Indeed the hour is a mixture of the poetic and the acidic. She punctuates the pomposity of the Mumsnet website with list of unreasonable demands on the Albanian nanny with the refrain 'am I being unreasonable?', reading like feisty performance poetry. Elsewhere Metro's poll of the most inspiring woman is cut through with a sardonic edge highlighting the vacuous nature of media, and there's a similarly sarcastic deconstruction of Dan Brown's incredibly clunky prose.

Bourke has the uncanny ability to draw you into to her world and on to her side, there's a lovely gossipy piece about a young American comedian with whom Bourke gigged in Dublin who has with a lot to learn about comedy, and history and geography too.

Hers is a no-nonsense approach. She'll stand no messing, as three fellas, who were obviously not committed to the show, found out. Unfortunately it happens a lot in free shows, because the lack of financial investments means some punters seem to think it's OK to drift in and out. Sensing that they weren't entirely happy Bourke asked them to leave, which they duly did. Despite noting how awkward that had made the gig and that she had to win around the audience again, she didn't really have to, she had us on side already.