The Traverse provides a safe bet for the wandering and wondering Festival punter.

In David Ireland’s Ulster American, an initial meeting between an ambitious British theatre director and Jay, a brash US Oscar-winning star of Irish Catholic descent, here to appear in his new play, seems to signal a fairly standard comedy.

When the female Northern Irish playwright Ruth arrives, things take on a cutting edge as religion, culture, politics and nationalities clash.

The dialogue is sharp and, as a reviewer, personally uncomfortable. Describing critics as animals, Jay asserts “We should … kill them and eat them. And the good ones keep as pets.”

Class by Iseult Golden and David Horan is another play that develops from a conventional situation — parents called into school to discuss problems with their child — into more controversial issues.

Mr McCafferty is devoted to his pupils but comes up against Brian suffering from anger management and separated from wife Donna — neither recalls good school experiences.

The conflict becomes one of class as the teacher tries to explain the issues in unintended patronising “technical” language — “percentiles” and “disparities” — and the gulf widens.

Stephen Jones and Sarah Morris double as the kids in McCafferty’s Homework Club in a play that will be recognised only too well by both teachers and many parents.

Two one-woman shows make interesting contrasts.

In The Greatest Play in the History of the World Julie Hesmondalgh’s monologue recounts a quirky love and loneliness story. Her delightfully engaging soft northern voice introduces us to Tom, waking in his bedroom on Preston Road to find that time has apparently stopped at 4.40am, and to Sara the girl across the road he has often wondered about.

His neighbours, the elderly Mr and Mrs Forshaw, busy in their mysterious garden shed, are in fact building their Kakudni, a version of the Tardis.

All this is linked to the Voyager golden record sent off into space informing alien worlds of the nature of ours. In fact, this warm and comforting view of the possibilities within human relationships offers more hope than any space exploration.

Anything but comforting, Coriolanus Vanishes is intense throughout as we gradually learn that Chris,  superbly played by Irene Allan, is on trial for murder.

Her shifting moods, appealing and then aggressive — “I don’t want to be that person” — reveal a schizophrenically damaged personality as she struggles with her bisexual life experiences.

Shifting character changes are orchestrated by Nich Smith’s lighting, while writer and director David Leddy keeps us skilfully off balance, questioning our judgements of Chris.

Every play-goer sees his or her own play. This needs establishing as Underground Railway Game has won so critical plaudits.

Supposedly treating the history of race relations in US, it opens as a lesson to a high school class (the audience) and moves into a pornographic, sadomasochistic, masturbatory scene between teachers Jennifer Kidwell and Scott R Sheppard — is there a US Ofsted, I wonder? — presumably intended to reflect the cruelty at the heart of race exploitation.

Two problems, no three. It is black Kidwell who is handing out the treatment. Surely it was the whites maltreating the blacks. White cruelty was primarily economic not sexual. Finally, pornography for all the hype is boring.

It was a relief to turn to Mark Thomas’s Check Up: Our NHS@70. Apparently our treasured health service is in difficulties.

Understandably, Thomas doesn’t treat the issues he exposes, through his month-long engagement with various figures at the heart of the service, as a laughing matter.

His characteristic ebullience and faux benevolent humour brings home the full nature of the crisis we all face.

GORDON PARSONS