When a dead body is found in the Thames, caught in the chains of HMS Belfast, it begins a search for a missing woman and confirms a sense that, in London, a person can become invisible once outside their community - and that assumes they even have a community. A policeman, a documentary filmmaker and an Irish nurse named Chrissie all respond to the death of the unknown woman in their own ways. Linda Grant weaves a tale around ideas of home, and how where we live can become a place of exile or expulsion.