Dr. Rhodes treats his mentor and Goodman faces personal issues in the Season 1 finale. Also: April deals with a disorderly patient; Dr. Manning's past catches up with her; and Sarah's graduation day arrives, but she remains conflicted about her future.

Dr. Manning and Dr. Rhodes separately treat complicated cases involving sick babies, only to uncover that the two cases could actually be intertwined. Elsewhere, Dr. Halstead and Dr. Charles treat a homeless man with an upbeat disposition who sheds some valuable insight that prompts one of the doctors to learn a thing or two along the way. Dr. Choi has a Navy corpsman follow him for the day as they deal with the toll of gang violence in the city, while Dr. Reese tries to understand the delicate balance required in her new position.

Dr. Manning and Jeff Clarke are forced to figure out a mystery illness when an Indonesian man who doesn't speak English arrives at the hospital in dire straights. Maggie takes Dr. Halstead to her family reunion. Dr. Rhodes takes on a complicated heart surgery without consulting Dr. Latham. Dr. Reese and Dr. Charles encounter a woman experiencing an unusual pregnancy.

Several patients are discovered to have the same rare infection, prompting Dr. Charles' daughter Robyn, an epidemiologist, to be brought in to find the common link. Dr. Choi and Dr. Rhodes work on an elderly man who is discovered to be very ill, but a conflict in how to best treat him develops between his son and his young girlfriend. Meanwhile, Dr. Reese tries to help a young drug addict and Maggie tends to a patient who is dear to her heart.

A car accident that occurs at the Chicago Marathon leaves a victim in critical condition and tests the mettle of Dr. Halstead, April and her fourth-year medical resident brother Noah, who must perform a difficult procedure in the field. A mother brings in her 8-year-old girl experiencing a sudden hearing loss and Dr. Manning is left to tend to the case, which takes a complicated turn. Dr. Choi deals with Olga, a woman who is malnourished, prompting him to bring in Dr. Charles to help assess the case. Meanwhile, Goodwin takes measures to get her personal life in order.

Sharon Goodwin's childhood sweetheart arrives at the hospital, but finds himself in dire straits. To help get his financial footing, Dr. Halstead gets lured into a concierge doctor app idea. Meanwhile, a young woman with a heart infection is treated by Dr. Rhodes against Dr. Charles' advice and Reese's former patient, a sex trafficking victim, reaches out to her for help.

Dr. Halstead and Dr. Manning deal with two warring brothers who are brought together when one finds himself in desperate need of a kidney. Dr. Reese's former patient Danny comes to a crossroad. Dr. Rhodes and Dr. Latham treat a 16-year-old girl with a genetic condition in need of surgery, but whose overprotective mother disagrees with that course of action. A convict with unusual intentions puts himself in the hospital and Dr. Charles meddles in his daughter Robyn's personal life, much to her dismay. Meanwhile, Dr. Halstead and April make a discovery that complicates her treatment for TB.

Dr. Rhodes convinces Dr. Latham to join him for a medical trip out of town. Dr. Manning treats an 8 year-old cancer patient who wants to give up on his battle. Elsewhere, an unhealthy woman with heart problems is brought in and doesn't want to listen to doctors. Meanwhile, Dr. Choi, Dr. Charles and Dr. Reese work on a complicated case involving a woman with a personality disorder.

A suicide shakes the staff. Dr. Choi and Dr. Halstead face off over how to treat a patient with stroke symptoms. Family turmoil unfolds when a boy is treated after falling in a river. The importance of learning from mistakes is emphasized to Dr. Reese.

Will is troubled with a moral decision when his former teacher, Dr. Bella Rowan, is faced with a life-threating disease. Dr. Rhodes and Dr. Bardovi get involved in a sensitive situation when Rhodes disagrees with the father of a young patient regarding a risky procedure. Dr. Charles and Sarah handle an unusual case with a pilot that causes Sarah to have memories of Jason Wheeler's suicide. Maggie takes an aggressive approach to training a new nurse.

A hacker demanding a ransom payment shuts down the hospital computer system, forcing the doctors to diagnose patients without the aid of technology. A stressed Goodwin struggles to keep the hospital afloat when an unexpected visit from her ex-husband Bert and his new girlfriend make matters worse. Making use of his former navy experience, Dr. Choi and Noah have to locate a bullet inside a patient with a gunshot wound. Meanwhile, Sarah feels Dr. Charles may be trying to push her out and Robin's unusual behavior worries Dr. Rhodes.

Things get personal for Dr. Halstead when his unsupportive father is admitted to the hospital against his wishes. When treating Will's father, Dr. Rhodes reflects on his relationship with his dad. Dr. Charles gets involved when his daughter Robin's strange behavior continues to intensify and Dr. Choi struggles to help a teenage boy who is desperate to control his sexual urges. Dr. Manning feels the impact of being a working mother when a young boy is brought in for neglect. Meanwhile, Sarah teaches a group of high school students about the responsibilities of having a child by using fake baby dolls.

Dr. Rhodes fights to save a mother who's desperate to help her daughter beat cancer. Dr. Charles asks Sarah to conduct his daughter Robin's psych evaluation. When Will and Dr. Manning spend more time together at work, Nina goes to extreme measures to get Will's attention. Meanwhile, Dr. Choi puts pressure on Noah when a residency spot becomes available.

Dr. Rhodes challenges Dr. Charles and other hospital staff over the proper treatment for Robin. Dr. Manning seeks help from Det. Halstead when a sensitive case involving a young girl turns into a crime. Dr. Choi and April work together on a conflicting case. Meanwhile, Goodwin helps a friend in distress and, after eagerly awaiting, the doctors are surprised to learn who the new med resident is.

A new hotshot doctor arrives at Chicago Med causing competition for Dr. Rhodes, Dr. Halstead and Dr. Manning work together to diagnose a Syrian refugee without a medical record. When Robin is admitted back into the hospital for more complications, Dr. Reese takes a different approach to her treatment. Distracted from work because of Robin's worsening case, Dr. Charles is challenged by Goodwin and Noah hosts a graduation party that brings everyone together.

Halstead hides the theft of his gun from a suspicious Manning. Tensions are still high between Connor and Bekker, who take a risk operating on an HIV-positive patient. Hank breaks down when he sees a patient from his past.