A floating double helix assembled from readymade steel staircase modules is the crowning centrepiece of O’Brien’s Frieze prize exhibition. These weighty sculptures hang in the air adorned with chrome balls. The spirals hide behind comically giant, loose-knitted stockings stretched over the forms’ voids. Hundreds of acrylic panels frost the gallery’s windows nearby, as though to form a horizon.

This is intriguing by scale and slightly odd in composition, but the effect is hardly worth a prizegiving ceremony. There is no discernible rationale for O’Brien’s materials to have come together so and no narrative emerges from the tonnes of steel and plastic his work consumed. Next door, the artist hastily installed a bunch of steel traffic bollards in glass display cabinets salvaged from a 1970s department store. Why is anyone’s guess: the work entirely fails to account for itself. Its only redeeming feature is that despite their simplicity, these smaller structures are somehow more disappointing than the steel DNA hanging.