When Sam's former boss wakes up months later demanding to resume his duties, she is tasked with supervising this egotistical expert with a scalpel who never acknowledged her stellar talent. Complicating matters, the caustic and arrogant Griff also happens to be her father. As he defies Sam's authority and challenges her medical expertise, the big question becomes whether this father and daughter will ever be able to mend their own relationship as expertly as they heal the hearts of their patients.

Dr. Sam Griffith fights to keep her new leadership role as chief of surgery when her father and former boss, Dr. Rob "Griff" Griffith, takes his case for reinstatement directly to the hospital board. Also, resident Dr. Caleb Tucker, Sam's ex, forms an unexpected connection to a patient battling a mystery condition.

When Sam refuses to concede her role as chief, her father orchestrates a costly surprise. Also, Sam's mother, hospital administrator Vivian, turns to her new spouse, therapist Asher Pyne, for help navigating the battle between her daughter and ex-husband.

When Dr. Sam Griffith tracks down a deep-pocketed anonymous hospital donor, she's shocked to discover why the donor is so loyal to her father, Griff. Also, Griff offers to mentor his daughter and assure her succession.

When aballoonshot victim is rushed to the ER, the incident triggers flashbacks to the aftermath of Griff's own shooting, and reveals new details of how the people in his life were affected during the six months he was in a coma.

Secrets revealed at a major fundraising gala for the hospital threaten to end a tenuous truce between Dr. Sam Griffith and her father, Griff. Also, cardiothoracic resident Dr. Lex Trulie makes a decision that could alter her career trajectory.

Dr. Sam Griffith deals with the fallout following her actions at the hospital fundraising gala, and Griff returns to the OR for the first time since his shooting to perform a bypass surgery. Also, Malcolm's estranged mother, hospital board chairwoman Tina Kingsley, arrives in town.

When Amy Taylor is admitted to the hospital accompanied by her sister, Gretchen, with signs of premature heart disease, Dr. Sam Griffith discovers a deeper medical mystery. Also, Griff anxiously awaits the results of his MRI, hoping to get to the root of his troubling symptoms.

When a devastating storm leads to an overflow of patients and limited resources, Dr. Sam Griffith and her team are forced to make impossible choices about their patients' care. Also, Dr. Rob Griffith connects with a young patient admitted with a rare heart condition.

In the aftermath of a devastating storm, Dr. Sam Griffith and her father, Griff, come together to support her injured mother, Vivian. Also, Dr. Lex Trulie and Dr. Joey Costa each make pivotal decisions about their futures.

As Griff completes his proctorship and prepares to make his official return to surgery, hospital board chairwoman Tina Kingsley makes a stunning announcement that threatens the future of Lakeshore Sentinel. Also, Lex meets her no-nonsense new boss, and the conflict between Isan and Joey comes to a head as the surgical team prepares for a high-stakes lung transplant.

As Sam, Griff and Vivian face the fallout from Griff's bombshell confession to the hospital board, the surgical team preps for a rare high-profile surgery that could take Sam's career to the next level. Also, Lex confronts Griff about his betrayal, and Malcolm sets his sights on his mother's board seat.

The battle between Sam and Griff takes a shocking turn that will irrevocably change their family dynamic and the future of the hospital.