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.

Devon and Conrad race against the clock to save the life of a woman who is deteriorating fast from undetermined symptoms. When the patient turns out to be a hero who helps previous criminals get their lives back together, the team relies on her family of ex-cons to help diagnose and treat her. Tensions rise as Nic continues her search for evidence to incriminate Lane, but must simultaneously tend to her sister, Jessie, who is rushed into the ER. Meanwhile, York returns to the hospital with his mother, who is in need of a risky procedure, and comes face-to-face with the stone-cold Dr. AJ Austin.

A blackout at Chastain Memorial Hospital requires the staff to treat their patients without the help of any technology. Bell orders the staff to stop accepting new patients and transfer those on life support, but when a child in need is rushed to the ER, Conrad and Devon go against the mandate. Meanwhile, Mina and Austin are tasked with performing heart surgery on a premature baby, despite the lack of power, and Nic works tirelessly to organize the staff and patients who stay during the blackout.

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.

Chastain is flooded with concert goers when a stampede at a music festival grounds leaves many in need of doctors. As Conrad and Nic race to help Josh Robinson, a professional adventure guide with a long list of prior injuries, Devon works with a musician who swears he is sober, even though his toxicology report suggests otherwise. Meanwhile, Bell stirs the pot when the hospital's revered orthopedic surgeon, Dr. Kit Voss, demands a better resident, Julian works to get her boss on Bell's good side and Winthrop continues to push Conrad to believe he's a changed man.

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.

Conrad goes head-to-head with Bell after he recommends one of Julian's risky medical devices to Zoey, who's already lost one son and is back in the hospital with the other. Nic fears that Conrad may be getting overly attached to his patient. Meanwhile, Mina and Austin grow closer while working on a difficult heart transplant, Devon embarks on a very difficult day and Dr. Lane Hunter returns.

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.

Conrad, Kit, Mina and the Raptor work to save the life of a med student in need of a triple-organ transplant, drawing Bell back to the OR for one of the Chastain's riskiest surgeries yet. After the police find Julian's empty car in a nearby lake, Devon does some investigating of his own to find out what might have happened. Meanwhile, Mina and the Raptor hound Bell to halt his business with the risky medical device company, Quovadis, and Nic makes a rash decision regarding her sister.

When Conrad's attempt to surprise Nic with a lavish Valentine's Day dinner is foiled, he gives the reservation away to someone who could really use it. Mina and Devon distract themselves from all Valentine's celebrations by trying to figure out how their seemingly healthy neighbor has suddenly passed away. Meanwhile, Kit gives dating advice to a sex-injured patient, Irving hits a crossroads in his not-so-secret relationship with Nurse Jessica, and Bell decides to celebrate the day in the OR.

Bell's confidence in Quovadis continues to waver when the poster child for one of its medical devices, Henry Barnett, is rushed back into the ER, experiencing seizure-like symptoms. Meanwhile, Mina's past comes to light when her mother, famous Nigerian surgeon Dr. Okeke, pays a visit to Chastain, and Conrad makes a risky move when Henry returns to the hospital.

The surgeons are determined to shut down Quovadis after Henry Barnett almost loses his life due to a device malfunction. As Mina and Devon set out to find the truth, Bell, AJ and Conrad work to save the life of Chastain's favorite custodian, Simon. Meanwhile, one of Alec's old patients ends up in the ER, forcing him to question if he made the right choice to leave his old practice for Nic's clinic.

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.

Bell hopes that a lottery winner who was admitted to hospital could serve as a way to solve Chastain's financial struggles; Nic is irate with Alec for suggesting she meet an organ broker; Devon and Irving help Mina remember certain details.

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.

Conrad doubts Devon's judgement when a patient who was pronounced dead suddenly revives. Cain and Nick butt heads over the care of a white supremacist. The Raptor and Mina uncover new information about Red Rock Medical.

After a plane crashes in Atlanta, Devon is overcome by guilt at the thought that he could have prevented it. Adaku returns to ask Mina a big favor. Conrad and Nic consider risking it all to investigate a drug that might be linked to Jessie's death.

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.

Conrad comes under fire when a former patient files a malpractice lawsuit against him, putting Bell in a difficult position with Red Rock. The doctors perform a risky brain surgery. Mina discovers that Adaku has a dangerous heart condition.

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

After being terminated, Conrad has difficulty figuring out his next step and distracts himself by accompanying a patient on a zero-gravity adventure. Cain puts the doctors on a commission-based pay system. Bell's company gets its big break.

Nic and Mina treat a patient battling a failing heart VAD, forcing them to find a new battery to save her life. Conrad gets a call from a patient who is in crisis. Cain tries to get close to Bell's business partner from the supplement company.

Conrad meets with a high-profile soccer player suffering from mysterious symptoms. Nic springs into action when she notices Kyle falling into a deep depression and fears he could be suicidal. Devon butts heads with Irving over patient space.

When Nadine's father comes to town for her birthday, Devon enlists help to ensure that he makes the best first impression. Red Rock decides to cut the entire OBGYN department. Nic cares for a teenage patient whose condition is deteriorating.

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.

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.

Just when Derek's condition seems to be improving, a severe complication arises, causing Kitt to fear that he may be the latest victim of Cain's cover-up. When Cain's former girlfriend is admitted to the hospital for surgery, the doctors finally get a glimpse into his personal life. Meanwhile, Conrad fills in Marshall on the emergency situation facing the hospital and Mina and The Raptor work on saving the heart of a salsa dancer.

After a long wait, Conrad and Nic prepare for their wedding day with the support of their family and friends. Meanwhile, flashbacks to the early days of the COVID-19 crisis shine a light on the heroism of the doctors and the toll the virus took on everyone at Chastain Memorial.

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.

On Nic's first day back at Chastain, the man who attacked her is admitted to the ER, causing her to confront her trauma head-on. Cain, now in recovery, is self-conscious of his physical state and sets his eye on taking down Mina. The new intern both struggles and shines throughout her first day, causing Devon and Conrad to wonder if something bigger is going on.

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.

When a tornado touches down in Atlanta with Chastain directly in its path, the entire staff goes into crisis mode. Conrad and Nic work on an injured EMT. Devon and Leela become trapped with a man who has severe head trauma.

An attack by cyber criminals sends the Chastain ER into a tailspin and Kit tries to figure out whether or not to pay the ransom. The Raptor deals with a personal connection to the patients brought into the ER during the attack, leaving them all vulnerable. Meanwhile, Conrad works on balancing life as a new dad and Devon and Leela debate taking the next step in their relationship.

While looking for a distraction on Halloween, Conrad treats a group of witches who send the ER into chaos. Also, Devon treats a patient who thinks he is being haunted by ghosts. Meanwhile, on the way back from his vacation, Bell picks up a hitchhiker who is not what he seems to be.

A new group of interns, which include Billie’s son, Trevor, start their first day with Devon at Chastain. Kit and Bell try to convince Conrad to come back to Chastain and The Raptor’s mom ends up back in the ER. Meanwhile, Leela and Padma deal with an unexpected visit from their parents.

Conrad takes Trevor under his wing to care for a patient whose good luck seems to have run out. Leela struggles when given the decision to take full responsibility of her indecisive patient's life and The Raptor continues to try to figure out a care plan for his mother. Meanwhile, both Devon and Kit are stretched far too thin trying to balance everything on their plates

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.

A tragic accident occurs at Jessica’s sister’s gender reveal party, putting her brother-in-law’s life in jeopardy. Meanwhile, Conrad, Irving & Trevor work on an influencer whose life was put in danger by a risky cosmetic surgery. Then, Bell is cleared for his first surgery back and Billie is forced to face her past head-on.

Conrad treats one of Gigi's fellow classmates whose stomachache turns into something much more serious; Devon takes several interns to a senior living facility; Leela uncovers some unsettling news.

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.

Ian is faced with performing a surgery on a Jane Doe NICU patient while he continues to struggle with his personal issues. Meanwhile, Conrad asks Devon to cover his shift so he can spend a day at home with an anxious Gigi.