Three concurrent surgeries at the hospital push its staff to the limits. Determined to ease the pressure, Nic requests Jude for one of the operations, making Conrad jealous. Meanwhile, Dr. Lane Hunter sets out to discredit Nic's claims, Devon struggles with a patient who has an embarrassing problem and a charitable contributor comes to the hospital wanting to donate a lot of money to Dr. Lane's oncology program.

As Conrad battles a group of overly aggressive attending physicians on behalf of a patient with a mysterious chronic ailment, he also must face off against his father who has shown up at the hospital unannounced. When Mina goes out of her way to help a young man from her neighborhood who almost mugged her, Nic offers her assistance and discovers a secret that Mina has been keeping behind closed doors. While away from the hospital, Nic enlists the help of Devon to keep an eye on Lily, which leads him to an incredible find that has him questioning Dr. Lane's motives. Also, Renata's plans to poach a renowned surgeon from another hospital hit a standstill when Bell decides he doesn't agree with him.

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.

Nic and Conrad contemplate their past when they team up to diagnose a happy husband and wife who are both admitted to the hospital with mysterious symptoms. Bell and Marshall butt heads on a work trip when their cut-throat business tactics don't align. Meanwhile, AJ turns down a request from Bell despite Mina's forewarning, Devon continues to gravitate to medical device rep Julian and the staff gears up for Conrad's three-year anniversary at Chastain.

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.

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.

Lane Hunter's victims and their families become outraged when she is released from prison. Bell, although responsible for posting Lane's bail and getting her released, continues to be tortured by her manipulation. Meanwhile, Conrad uses work to cope with the news about his father, and he teams up with Mina, Kit and the Raptor to treat a patient who is suffering as a result of Lane's dangerous treatments. Then, Devon grows worried when he doesn't hear from Julian, and Nic sets her sights on a primary physician for their new clinic.

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.

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.

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.

On National Nurses' Day, the nurses are severely understaffed and overworked. Cain performs a dangerous surgery on a new patient. Conrad discovers that his father has been administered the same drug that he fears played a role in Jessie's death.

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.

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.

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.

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.

On the day of Nic's baby shower, Billie takes full control to make sure it goes smoothly, but a secret she's been hiding changes everything. Devon and Leela stumble upon an apartment fire, where they assist in getting victims safely to Chastain and Leela gets a chance to prove her skills to Raptor. Jake and his husband deal with the complications of Sammie's health. Raptor and Rose receive exciting news.

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.

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.

When an accident brings a familiar patient into the Chastain ER, the doctors must face the reality of figuring out how to proceed with the best care, which leads the whole staff questioning every decision. Meanwhile, The Raptor and Leela deal with a patient returning with the long-term effects of COVID.

In trying to find a way to channel his emotions, Conrad puts all his effort in looking for answers. Raptor has a run-in with the police that ends up taking a surprising turn. Meanwhile, Leela begins noticing problems with a surgeon who has been Bell’s mentor.

When things from Billie's past begin to come to light, she is the subject of whispers and stares around the hospital and the team struggles to find the best way to support her. With the nurse shortage in full swing, a simple cleaning job turns into a horrific disaster that calls for all hands on deck. Meanwhile, Trevor discovers a shocking secret and Padma has a proposal for Leela

After a teenage boy is taken into Chastain for falling unconscious from a suspicious pill, Conrad takes action to find the boy's brother before he meets the same fate. Meanwhile, Dr. Bell deals with being served court papers from a former patient.