Reese, the main character of the novel, is one of the most talented heart surgeons in the world. His desire to become a heart surgeon intertwined with his love for Emma, his childhood best friend and eventual wife. Despite being naturally gifted at working with the heart, Reese could not save Emma; having disappeared from the medical world, he lives as a recluse, and only his brother-in-law Charlie knows his real identity.

Reese’s serious temperament suited him as a surgeon, but in this phase of his life, it keeps himself distant from emotion, particularly joy—he sees loneliness as his penance, unlike Charlie, Annie, and Cindy, who find happiness despite personal tragedy. When Reese practiced medicine, he used stimulants taken from the hospital so he could perform multiple surgeries in a row without much sleep, believing each surgery would lead him closer to saving Emma. When exhaustion rendered him unable to save his wife, he blamed Emma’s death on his drug use.

For much of the novel, Reese feels immense regret, but his affection for Annie, his growing interest in Cindy, and his friendships slowly steer him toward happiness. He finally lets go of regret, embraces his calling as a surgeon, saves Annie’s life, and opens his heart to love again.