A shoot-out in the ER leaves Topher seriously wounded. TC tries to control his Afghanistan flashbacks. An explosion at a fertilizer factory sends burn victims to the ER, overwhelming the shorthanded staff. And Jordan discovers a secret about TC.

Scott and Jordan must perform surgery in the field as the burning wildfire gains intensity around them. Syd has caught Typhus along with hundreds of other patients on the Syria-Turkey border, and TC goes to great lengths to get the medication. Meanwhile, Drew and Rick fight to keep Brianna, while San Antonio Memorial finds an unlikely buyer, though saving the hospital comes at a cost.

A horrific crash sends dozens of soldiers, including Drew's boyfriend, to the emergency room, where TC and Scott clash. Meanwhile, Topher tries to diagnose a soldier's illness, and Kenny tries to improve Ragosa's online-dating profile.

A shooting at a nearby college sends TC, Jordan, Drew and Amira into the field, where they assist Rick with a deadly situation. Scott implements a new training program and locks horns with Julian. Drew struggles with frustrations about going to Army Ranger School while Shannon and TC both contemplate their future at San Antonio Memorial.

TC and Paul pull out all the stops when a crane collapses on a worker at a busy construction site. As Paul works tirelessness to save the crush victim, an observer falls into a deadly gravel pit. TC throws himself into the pit and races to save the patient before he's swallowed by the shifting gravel. Back at the ER, Scott is shaken as the teenage boy he paralyzed returns to the hospital with new complications. Jordan lends support as the emotional case exposes complicated feelings from the past. Meanwhile when a life-saving donor matches with cystic fibrosis patient, Brianna, Drew determines the depth of his feelings for her.

TC and Topher treat the lone survivor of a plane crash while fending off an intimidating law-enforcement officer with a secret motive. Meanwhile, Paul is smitten by an injured exotic dancer whose condition takes a turn for the worse; and Krista cares for a teen with an eating disorder.

A violent storm pummels San Antonio, sending numerous patients to the emergency room. Elsewhere, TC and Dr. Scott Clemmens rush to a mudslide disaster to treat a mother and her son; and Topher braves the storm to help his stranded wife, who's going into labor with twins.

T.C. and Topher return to find Jordan in critical condition and San Antonio terrorized by snipers; Drew and Gwen get caught in the crossfire when a SWAT team corners the snipers.

Drew and Paul head to the scene of a multi-car collision while the newly-anointed Dr. Ragosa along with Jordan, Scott, Krista and Kenny, manage the deluge of incoming victims. Meanwhile, TC and Topher head into a war zone to treat an old friend.

When a bomb explodes outside the hospital, TC, Topher and Drew are forced to make the tough decision to stay and treat the injured or evacuate and begin transfers to nearby hospitals. Everything changes when TC suddenly realizes he may know the person responsible for the explosion. While the team works feverishly to tend to the wounded, the nurses go on strike just when the hospital needs them the most. Meanwhile, throughout the intense night shift, Shannon and Paul attempt to confront each other about something personal.

The doctors race to save Topher's mom when she comes to the ER with life-threatening symptoms. The team discovers a gravely injured foster mom is harboring a secret. Jordan asks T.C.'s girlfriend for help with a patient.

Kenny joins Drew at his MMA veteran's support group and finds himself in the fight of his life. Jordan and Cain treat casualties from a hotel fire while Shannon follows a hunch to help save a young victim. Paul's superstar sister, Dr. Bella Cummings, pays a visit to San Antonio Memorial. Meanwhile, TC finally returns home, forcing him to deal with Topher's death.

Jordan and Drew perform a daring rescue by jumping from a chopper. Landing at the nearest VA hospital, Jordan sparks a plan to appease Julian and reunite her night shift team. Back at the hospital, Paul deals with the repercussions of standing up to his father while Scott dives headlong into his professional life. Kenny butts heads with Cain, a traveling nurse with a mysterious past. Shannon indoctrinates Cain as they work in San Antonio Memorial's understaffed and overworked ER. Meanwhile, TC is held captive in Syria. In order to find Syd, TC must treat his captor instead of returning to the safety of an air base with a civilian volunteer, Amira.

Drew, his mom, and Rick's flight home turns into a medical crisis at 35,000 feet when passengers become sickened one by one. Jordan, Paul, Shannon, Kenny, and Cain spend their day off at an obstacle course fundraiser for Cystic Fibrosis, hosted by Akbar Gbajabjamila. Scott finds himself on a Tinder date he won't soon forget. Meanwhile, TC puts his own life in danger to operate on a soldier.

In the premiere, a former military doctor deals with a life-threatening situation on his way to work; his ex-girlfriend pursues the night shift's top job; and a clash over business matters unfolds.

The night shift is tested when a rancher accidentally shoots his wife. TC heads to a teen party to save the life of a young football star. Jordan and Kenny treat a beauty queen in severe distress. Topher makes a decision about his job.

TC and Paul race to the chaotic scene of an after-dark hog-hunting event that has gone nightmarishly wrong. Meanwhile, a 9-year-old girl arrives for treatment in a case that turns complicated; Drew injures his hand; and Ragosa seeks family counseling.

Injuries at an Alamo reenactment test the staff. Meanwhile, a disoriented patient suffering from amnesia receives care; Drew helps a severely wounded soldier; Topher schedules a vasectomy operation; and Jordan's boyfriend arrives.

As a thick fog descends upon San Antonio, the doctors must improvise to save the victims of a car crash; Topher, Drew and Kenny treat siblings injured in the fog.

T.C. discovers his sister-in-law's complicated history after he treats her for a fall down stairs.

Shannon and Jordan venture out for some fun at a local wrestling event only to find themselves treating people on site when a fight breaks out amongst the audience. Back at the hospital, Sam attends to a marathon runner who has collapsed from the heat and things start to heat up even more when the air conditioning breaks. Meanwhile, tensions between TC, Jordan, Sam, and Annie start to boil.

Jordan and Cain figure out their professional dynamic as they work on a patient with extreme injuries from an oil field explosion. Drew and Paul receive a patient from the same accident, and must figure out a solution to save the patient's severed hand. Scott is caught off guard when Annie shows up to the hospital with an unexpected guest from his past. Kenny and Shannon struggle to adjust to their new living situation. Meanwhile, TC and Amira clash over treating a Syrian child on the American base.

As the city erupts in violence over an impending jury verdict, the night shift becomes ground zero when they have to take in the man suspected of the racially-motivated shooting at the source of the unrest. His presence in the emergency room sparks sharp conversation and disagreements among the staff over the highly-charged topic and even close friends Kenny and Paul find themselves at odds. Topher does his best to control the mounting chaos in the ER while out in the field, TC makes a decision as to which of two patients to bring in, leaving Paul and Scott to question TC's motives.

A fireworks explosion creates chaos at a concert, sending patients streaming into the hospital as TC and Topher race to the scene. Syd returns from Afghanistan and faces her unique family dynamic. Jordan and Scott address simmering differences.

TC desperately tries to save his critically injured friend. Meanwhile, Paul tackles a challenging case involving an elderly woman; Kenny helps an injured groom with a secret; and a 9-year-old boy has suspicious injuries.

A building collapses during a rodeo; a severely injured cowboy exhibits strange symptoms; Scott causes a serious car accident.

In part one of this two-part season finale, Scott and Jordan face grave danger during a rescue mission at a rapidly spreading wildfire outside San Antonio. Tensions are high between Syd and TC as they find themselves in the middle of a humanitarian crisis on the Syria-Turkey border. Paul and Shannon argue over treatment for a patient. Meanwhile a major setback threatens Drew's adoption plans for Brianna, Topher struggles to find a buyer for the hospital and medication goes missing.

Topher takes over as chief of the night shift. TC is temporarily suspended. Jordan is scrutinized for her mishandling of the man who shot a recovered Topher. A father is trapped under an elevator. Ragosa returns to the ER.