Deirdre O'Callaghan has provided an unsettling but ultimately invigorating record of the inmates at Arlington House, Europe's largest refuge for alcoholics and the displaced. One hundred years ago Lord Rowton took it into his head to build a hostel. Being a peer of the realm the grandiose came easily to him, and in 1905 the massive, even forbidding, red-brick edifice arose in Camden Town in London, filled with 382 beds for impoverished manual labourers. Clean sheets, washing facilities and nourishing food were to be provided for the inmates. In fact the great building, Arlington House, was designed to be, and quickly became, billets for the destitute Irish navvies who crossed the sea to find work in the capital. Today the Irish connection has not gone; almost 70% of the current residents are Irish, and, although they are equally poor, few of them work or labour - most are alcoholics, and largely forgotten by society. A picture of Arlington House in the past can be found in George Orwell's Down and Out in Paris and London. It is not pleasant. Now the photographer Deidre O'Callaghan has brought together four year's work at the refuge, her record of the despair, humour and hope on the faces of the residents, a remarkable gallery of a largely expatriate community at odds with the world outside. But her pictures also record the work of the hostel itself in trying to reintegrate the residents into that world, photographs of clarity and wonder taken during trips to Ireland for the inmates. Some have lived at Arlington House for 30 years; many have not seen their families for as long. Her pictures of these reunions with their kin and their country are remarkable.