Ripley struggles to keep Sully's diagnosis a secret when the latter's pregnant girlfriend comes to Med for help. Johnson works to earn a spot in Med's trauma fellowship. Charles and a medical student treat a bipolar artist.

An infection threatens Marcel's risky liver transplant. Maggie and Charles help a struggling burn unit nurse. Goodwin is forced to make a tough decision about Bert's future.

Ripley and Charles treat a high-risk prisoner who may have dementia. Archer and Sean clash when a resident from Margo's facility lands in the E.D. Marcel receives shocking news.

When a commuter ship capsizes, the ED finds itself under water as the staff struggles to treat the influx of new patients and deal with bold new employees taking charge.

Lenox continues to rankle Archer as the two tackle their new roles. Ripley faces possible suspension over what really happened to Pawel. Goodwin is forced to make layoffs.

Halloween chaos takes over the ED. Asher helps a pregnant woman with an autistic son. Charles clashes with Nurse Jackie on a psych case.

Chicago P.D. steps up Goodwin's security after she's threatened online by a former employee. Archer and Frost treat victims from a disciplinary camp injured during a rockslide. Maggie gets roped into delivering a high schooler's baby.

Ripley and Frost uncover shocking information that conflicts with their patient's DNR. Asher facilitates an unexpected reunion. The tension between Archer and Lenox comes to a head.

An army of surgeons prepares to separate conjoined twins. Asher reconnects with someone from her past. Archer treats a tyrannical boss with a heart problem.

Lenox's mentorship is put to the test. Asher helps a religious young woman with an ectopic pregnancy. Ripley's self-destructive behavior continues to escalate.

Gaffney gets a surprise visit from a National Accreditation Board of Hospitals representative. Asher and Naomi search for the cause of a young girl's infection. Lenox and Frost work together to save the victim of an accidental shooting.

When her former patient returns to Med, Goodwin learns that time doesn't heal all wounds. Frost and Charles treat a patient struggling with his sexuality. Lenox and Abrams work to save a woman who has been in a coma for 20 years.

Asher makes a tough call to save a life. Frost and Ripley treat a young boy with a snake bite. Archer gives Naomi a patient to handle on her own on her last day in the E.D.

Maggie and Goodwin's friendship is tested as tensions rise during the nurses' union's negotiations with the hospital. Ripley and Archer treat a skateboarder struck by an emergency vehicle. Frost helps a young boy abandoned by his mother.