“Did you have a super trip?” agonises Cora, asking her newly returned sister about her travels. Only moments ago she rehearsed the question alone in front of a video camera, speaking with crystal-cut eloquence. Reality, it seems, is harder to manage.

Ellen Flynn’s enlightening new play for BridgeTalk Theatre has the makings of an absorbing mystery: Leah (Seana O’Hanlon) is back from a long absence to put something to rest, a past event for which Cora (Maeve O’Mahony), suffering from nerves, fears she will be blamed. The latter’s husband Egan (Ross Gaynor), a filmmaker fishing for a story, revolves dangerously around them with a camera. Will a devastating truth between sisters be uploaded onto Youtube?

O’Mahony’s Cora is fascinatingly gormless and O’Hanlon’s Leah nicely guarded but, as the title suggests, it is Gaynor’s slippery Egan who calls the shots. The stage itself is placed under surveillance in Bill Woodland’s design, both by a live video feed and a surreal bough suspended overhead.

But is it believable? Cora and Leah, showing worrying signs of alcoholism and depression, will protest against Egan’s recording but still continue their displays for it. Why haven’t they long since walked away or, better yet, seized the camera and smashed it with Cora’s Chardonnay bottle?

It turns out that the gadget is a relic belonging to their lost brother. That may seem a strenuous device through which to sustain Flynn’s exploration of human attachments to technology. Yet Egan rightly suspects Leah’s need to give a confession, as if the testimony isn’t meaningful unless it’s frozen in pixels. This compulsion is believable in a culture obsessed with the digital, but in this staging such desires require greater interrogation.

Under Laura Bowler’s direction, Cora, Leah and I plays up Cora’s bourgeois ignorance (“‘thrift’ … is that how you say it?”) while maintaining the twists of a psychological thriller. The tone of the staging falters, however, with the bizarre arrival of a cat carcass. Is its presence meant to stir, rouse laughs or both? In practice it disrupts an otherwise measured production.

A later scene, intimate and without devices, is more rewarding. Cora and Leah delicately address their trauma, and the viewer feels a considerable amount of empathy for them. Before long, Egan’s footage is being employed to plot the sisters against one another and everything falls apart once more.

All of this combines to make Flynn’s play a searing drama about mining private grief for public spectacle. The downside it that it doesn’t have the staging to match it here. The final beat is played as a glimpse of empowerment, with Cora turning the camera on Egan. “Wiggle your toes for me,” she demands. But lurking behind this ending is a sense of something darker: a devastating cycle of surveillance.

Cora, Leah and I is on at the New Theatre in Dublin until 25th February 2017. Click here for more details.