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.
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.
Reese and Finch's latest Person of Interest is a down-on-his-luck man (guest star Myk Watford) who may have reached his breaking point. As the case evolves, the duo calls upon a former POI for help, the resourceful and well-connected fixer Zoe (guest star Paige Turco).
It's Reese's birthday, and Finch gives him a day off – especially when he realizes that The Machine's latest number is certain to revive painful memories.
Holmes returns to New York with a new apprentice and a renewed interest in working with the NYPD after being fired by London's MI6. However, Captain Gregson won't let him resume consulting for the department without permission from his former partner, Watson, the NYPD's new go-to private investigator. Gina Gershon and Ophelia Lovibond guest star.