Daisy is the Nan of a poverty-stricken family and devoted friend of the dying Nellie O'Brien. One dark night, cornered by three drunken sailors, Daisy yields herself to them and when they pay her, she realises how she can earn a living. She becomes the toast of the waterfront, managing to hide her occupation from her family. When her stoker husband returns from sea she realises, terror-stricken, that the moment of truth has arrived.