Did anyone know Dr Gabriel Beaufort better than Ruby Rose Gillespie? They were friends at high school. They are secret lovers now. And because he is also the lung-transplant surgeon who saved her life, Ruby will forever be in his debt. But then the body of Dr Beaufort is found in the wetlands next to the hospital, on the same day as Ruby, a person who lives with cystic fibrosis, is readmitted with a sudden fever. As the crime scene investigation begins beneath her hospital window, Ruby starts to gather her own clues about her lover's last movements. But with each new discovery, she is haunted by the question of whether she really knew Gabriel Beaufort at all.