He is a tattoo artist, though he does not believe there is any art in what he does. He goes from tattoo parlor to tattoo parlor across the country applying poetry on people's skin. The organization he works for pays the people to be the canvas. The poems that are placed on the people will quickly fade, leaving only a memory of what was placed upon them.
She is a photographer who goes from city to city taking pictures of walls. The walls her organization wants her to document have strange formations of mold on them. She does not see herself as a photographer or an artist. Just as someone who does a job she does not care to comprehend. He and she meet in various cities that they are both assigned to work in. They form some type of relationship.
You are the reader. You in your new lover's bed. You are reading the book on his skin. You are interested in the story. But mostly you are awake and he is asleep and the least you can do is read the book to find out what happens.
And maybe you are finding out what happens in your own life, as your lover sleeps. As you read a book on his skin.