In his downtown Toronto condo, Dr. Chen awakens to the sound of streetcars below, but it is not the early morning traffic that keeps him from sleep. News banners run across his phone: Fentanyl Crisis; Toxic Drug Supply; Record Number of Deaths. From behind the headlines, on the same screen, glow the faces of his patients, the faces of the what-ifs: What if he had done more, or less? Or something different? Would they still be alive? Claire is a violinist; she feels at one with her music, taking flight in its melody, free in its movement. But now she rises and falls with the opioids in her system, becoming increasingly reckless. After two overdoses in twenty-four hours, she sits in the blue light of her computer, searching a notice board for recommendations: my doctor saved my life; my doctor is just another dealer. And then another message catches her attention, about Chen's clinic: be a guinea pig--why not get paid to take it? When Claire's life intersects with Chen's, the doctor is drawn ever more deeply into the complexities of the doctor-patient relationship, the implication and meaning of his intention to treat. Chen must confront just how far he would go to save a life.