After a subway tunnel caves in, Ruzek and Kidd help injured passengers and pursue a suspect. Archer and Frost amputate to save a life. Lenox shoulders CPD's expectations while trying to save a colleague.
The team fights to save the life of one of their own. Frost and Abrams butt heads with their patient. Asher helps a religious young woman with an ectopic pregnancy.
The hospital goes into lockdown mode when a man with a gun holds medical staff hostage. Goodwin is forced to make a tough decision. Dr. Rhodes begins to realize his time with his father is getting short.
Ripley struggles to rescue a woman and her daughter trapped in an abandoned well; an old friend from Frost's TV days shadows Maggie; Asher discovers an extremely rare condition in her patient's ultrasound.
Goodwin's troubles persist. Charles clashes with his former resident over a depressed patient. Lenox and Ripley treat a car accident victim who recently reunited with his college sweetheart.
Charles and Archer care for a heart recipient convinced his transplant rejects him. Lenox is off for a personal day. Hannah finds an ovarian mass in a pregnant patient.
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.
An entire apartment complex is forced into quarantine when cases of the deadly virus turns into an epidemic. P.D. chases a lead that could point to a case of bio-terrorism and Will gets dangerously close to the suspect.
Asher treats a woman whose undiagnosed condition threatens the lives of both her and her unborn child; Goodwin receives a chilling message while battling the hospital higher-ups.
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.
