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.
Halloween chaos takes over the E.D. Hannah helps a pregnant woman with an autistic son.
Severide gets wrapped up in an Illinois State Police investigation after discovering illegal guns on a call. A bird harasses Mouch on the apparatus floor. Kidd keeps an eye on Carver as his attitude worsens.
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.
A familiar face returns to the E.D. Ripley and Charles treat a woman with a rare disorder.
