Scratch follows Lena, an art student who is living in London. She searches for inspiration for her art project and finds it in Sol. He is a scruffy young man who drifts around, engaging in seemingly detached relationships with a variety of people. Lena begins to follow Sol, gaining a voyeur's perspective on the young man's life, and taking pictures of him when he is unaware. Things take a wrong turn when Sol discovers her. He is fascinated by her odd behaviour, and so Sol is now the one following her. The two form a strange relationship, gradually exposing each other's dreams, fears and lies.