PoisonProject Arts Centre, Dublin★★★☆☆Bereavement creates an inevitable tension between mourning and moving on. We are compelled to honour the dead through demonstrations of grief but also to reconstitute life without them.That dual imperative lies at the heart of this two-hander by the Dutch playwright Lot Vekemans, first performed in 2009, which is receiving its Irish premiere, in a translation by Rina Vergano, in this Once Off production.An estranged, unnamed couple, He and She, here reunite at the graveyard where their son is buried, a decade after his death in a traffic collision. She (Rachel O’Byrne) remains fixated on the loss and has summoned her ex-husband (Naoise Dunbar), ostensibly because their son’s grave may have be moved because of poisoned groundwater.Though hardly devoid of grief, He has remarried and built a new life in Normandy, in northern France. The contrast between his readjustment and her agonised mourning quickly generates bitter conflict. “Do you miss him?” she repeatedly demands, sensing that He is eager to put the past behind him. He counters that her suffering has become an addiction.Under Lianne O’Shea’s direction, these exchanges are rich in emotional texture. Lacking any means of processing her trauma, She bristles with anger that He is not equally overcome by despair. He, conversely, seems evasive and somewhat callous. That coldness is driven in part, we come to realise, by a desire to cover up his guilt at having walked out on her after their son’s death.He will, however, eventually summon a burst of passionate intensity to match hers. That shift is adroitly handled by Dunbar. But there is also possibly a darker subtext that is only hinted at in this staging. The conflict between the former husband and wife has the flavour of an unresolved power struggle in which performative grief serves as a psychological cudgel.Of their dead son they say remarkably little. What they really seem to care about is trying to dominate each other, She by shaming him, and He by vowing to write a book about what happened. Lurking behind their displays of anguish is, perhaps, a deep strain of mutual narcissism.Once He has delivered his cry from the heart, Poison nonetheless moves towards an emotional truce, if not quite reconciliation. While creating structural balance within the 70-minute running time, that shift is accompanied by a drop in the dramatic temperature. In the absence of vituperation, the thinness of the characterisation becomes apparent. He is a frustrated journalist; she once suffered from a chocolate addiction. Their worlds otherwise remain rather blank.Poison: Rachel O’Byrne and Naoise Dunbar in Lot Vekemans’s play. Photograph: Marcin Lewandowski Another weakness lies in the incongruities of Sarah Bacon’s design. The action is framed by strips of dark wood panelling of the kind you might find on the walls of a spa or a Japanese restaurant. Three strips of fluorescent lighting overhead don’t add much to the atmosphere.Though both He and She here become recognisably Irish, the setting implicitly remains somewhere on the Continent. When talking to his new wife on the phone, Dunbar’s difficulties with French pronunciation further contribute to a muddled sense of place.Poison, staged by Once Off Productions, is at Project Arts Centre, Dublin, until Saturday, June 6th