Conrad and Devon work tirelessly to save the life of Bradley, a fellow doctor who has fallen through the hospital skylight. As the team contemplates how and why he fell through in the first place, Dr. Bell looks back to when he benched Bradley for falling asleep during surgery. Amidst the madness, Mina is tasked with showing Chastain's new star cardiothoracic surgeon, Dr. AJ Austin, around the hospital, but is caught off-guard by his volatile personality. Meanwhile, Nic finds renewed enthusiasm when she uncovers an oncologist who used to work with Lane, but while paying him a visit, she fears that she's being followed.

When a nasty flu season turns out to be masking a terribly infectious disease, Chastain must race to quarantine and diagnose infected patients. Mina finds herself testing Quovadis medical devices in an effort to defend Dr. Austin, who, feeling responsible for the death of a patient, is serving penance by staying away from the OR. Conrad is prepared to take the next step with Nic, but finds that she may not be as ready.

Chastain picks up the pieces after the fall out with the corrupt medical device company Quovadis, leaving Marshall ready to charter new territory in the medical field, and Devon to finally discover the truth about what happened to Julian Booth. As Conrad and Alec team up to help a young gymnast experiencing mysterious symptoms, Nic focuses on her sister, who's back with their estranged father, Kyle, in tow. Meanwhile, Bell rushes to Kit's aid when her ex-husband comes to the ER needing emergency surgery.

Devon and Irving are inundated with patients in the ER. When an A-list celebrity enters the hospital after swallowing a wishbone, Logan Kim assigns a new surgeon to the case in the hopes of garnering extra publicity.

Cain recruits Ezra to help keep an emergency situation under wraps. Nic works to come up with a support system for a patient in need of a lung transplant. Kit's son-in-law's condition continues to worsen.

As Nic struggles with her recovery, her close friend and former Chastain colleague, Billie, comes back to the hospital to support her. Meanwhile, as the hospital transitions from private to public, the search begins for a new CEO, Bell asks a favor of his step-son and Devon sees an opportunity to fix the system.

With Nic's due date steadily approaching, she and Conrad plan a relaxing day off, but their plans are interrupted when a patient with a medical mystery sends them rushing back to Chastain. Devon stays by Rose's side as she starts her clinical trial and things take a turn for the worse. Meanwhile, Kit is under pressure to bring Chastain out of debt.