Now You See Me by Lesley Glaister
Since walking out on her life at sixteen, Lamb has lived alone in the gaps between other people's lives. Secretly inhabiting the cellar of an elderly man for whom she cleans, she keeps herself to herself, her life a precarious balancing act - until she meets Doggo, a young criminal on the run. Both strangers to the concept of truth, Doggo and Lamb are drawn together, glimpsing in one another the possibility of finding solace and maybe even love. But with secrets too dark to admit to even themselves, let alone someone else, first they must just learn to trust in each other.