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 film maker and an Irish nurse named Chrissie all respond to the death of the unknown woman in their own ways. London is a place of random meetings, shifting relationships - and some, like Chrissie intersect with many.