An old army buddy and fellow surgeon visits Conrad at the hospital. Meanwhile, the team is put to the test when they have to save the life of an uninsured and undocumented patient, while simultaneously battling the hospital's administrators, who fear the patient will cost millions. Also, Dr. Bell experiments with a new medication for his tremor and Nic swears to investigate the mystery surrounding missing medical records.

Conrad is hit by a bike and badly sprains his ankle, but works through it when he takes the case of his old medical professor, who is hallucinating visions of her old patients. Devon is tasked with admitting Conrad, who refuses any sort of treatment. Nic tries to navigate her emotions while mourning the loss of a patient and Bell operates on a foreign dignitary with unforeseen complications. Meanwhile, Lane and Bell's relationship grows closer.

In a final and drastic attempt to save Nic from Lane's acts of sabotage, Conrad must call in a favor from the one person he promised he never would. Meanwhile, Mina's partnership with The Raptor takes on new colors when Micah is rushed back to Chastain with major heart complications and Dr. Bell's alliance with Lane is put to the ultimate test when one of her patients is readmitted.

Bell grows frustrated when Marshall Winthrop, Conrad's dad and new chairman of the board, requests Conrad's input in his discussions about the hospital's expenses. As Conrad and Nic work to cut costs for their patients in need, Julian Lynn, a sharp and sophisticated medical device rep, meets the staff at Chastain and inserts herself into the ongoing work of the doctors to promote her costly products. Meanwhile, Mina's relationship with Micah struggles in the wake of his healing process, and Devon is tasked with showing the eager new interns around the hospital.

Halloween at Chastain proves to be just as spooky as ever when Conrad is tasked with diagnosing a young woman admitted to the hospital with extreme night terrors. Meanwhile, Devon faces his first Halloween in the ER, Nic panics over her decision to bring her newly sober sister to Mina's epic annual Halloween party and Bell finds an interesting way to make use of his new assistant.

Devon's doubts about his relationship reach a peak as his friends and family gather for his big wedding day. As Chastain's leading medical device company, Quovadis, continues to succeed, Julian makes a discovery that leaves her uneasy about her involvement in it all. Meanwhile, Conrad continues to work on his relationship with Marshall and Bell takes a risky offer in order to make a mistake from his past disappear.

The surgeons work together to save the life of the Raptor's old mentor, Abe, who is their only inside source to Quovadis. Unfortunately, when Nic and Conrad take on a patient needing the hospital's only viable ECMO machine, they must decide between saving the life of Abe or saving the life of their younger, more stable patient. Meanwhile, Marshall puts himself in serious danger to help take down Gordon Page once and for all.

In an effort to save Chastain, Bell considers selling the hospital to a conglomerate, but Kit tries to make him see that the negatives will outweigh the positives. With Conrad's help, Nic tracks down Kyle and pleads for him to reconsider donating a kidney to Jessie. Meanwhile, Mina voices her concern to Austin when Shira is assigned to Micah's surgery and Devon fights for the care of a patient whom the doctors suspect is uninsured.

When a police officer brings in an injured criminal, the staff must keep him alive. Nic gets roped into a surgical rotation with Cain that leaves her questioning the way he operates. Conrad makes a shocking discovery about the hospital.

Devon and Conrad face a moral dilemma over a suicidal patient who is in need of a liver transplant.

Conrad finds himself caught between his duties as a doctor and his loyalty to Kit when he discovers that her son-in-law may be suffering from a serious disease. Devon and Nic make a shocking discovery about a former patient.

With Chastain on the verge of shutting down due to the sale by Red Rock, Conrad tries a last-ditch effort to save the hospital and the doctors plan for their next career moves. Meanwhile, on their last day, the whole staff must work together to save Nic's life after she is injured by a deranged patient.

Just when Mina and The Raptor can see their future together, an unexpected complication throws a wrench in their plans. Meanwhile, Cain faces a harsh reality when Kit gives him the opportunity to prove he is ready to return to the OR. Then, Devon presents Rose with a groundbreaking clinical trial that could help her battle with Sickle Cell Anemia.

The wait is over as Conrad and Nic welcome the arrival of their baby girl. Raptor's life begins to fall apart and he is forced to turn to Cain for help. Devon and Bell work together on a complicated surgery that may allow them to save multiple lives. Kit tries to deal with the moral repercussions of financially saving Chastain.

When one of the doctors is found unconscious in an elevator at Chastain, the staff frantically retraces his steps to figure out the cause. Billie is faced with a personal conflict when she comes face-to-face with the secret she has been hiding all these years. Meanwhile, Bell helps Kit make a decision about a new neurosurgeon joining the team at Chastain.

When the first day of Kit's experimental Flight Go team program sends Conrad out into the field, he builds a new relationship with a fellow doctor along for the ride. Devon works with Trevor for the first time on a patient with a mysterious fever, the cause of which can't be found. Meanwhile, Bell is hiding a secret from the whole staff and they are starting to become suspicious.

Conrad contemplates his future; Devon is presented with an amazing career opportunity out of state; Ian is faced with a devastating diagnosis; Kit and Bell celebrate their engagement; Padma receives some highly anticipated news.

When a gunshot victim comes into the ER, his injuries prove to be so catastrophic throughout his body that multiple doctors need to jump on the case. Meanwhile, Ian is faced with a mandatory drug test and Padma prepares for her C-section.

Conrad is pulled away from celebrating Gigi’s 6th birthday when Sammie comes into Chastian with a 104-degree fever, and Kit must call in a favor for treatment. Meanwhile, a heart arrives for Governor Betz’s transplant surgery.