When paramedics rush in with a stabbing victim, Villanueva is stunned to realize that the patient is his own son, Nick (guest star Denzel Whitaker) Now it's up to Sydney and Hooten to save the young man. With Ty's help, Sung attempts to restore a concert violinist's perfect pitch by removing an astrocytoma that is pressing on the musician's brain. And Buck receives a strange request from the donor in a failed kidney transplant.