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.
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.
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.
Ripley and Frost uncover shocking information that conflicts with their patient's DNR. Hannah facilitates an unexpected reunion.