Everyone in the ER is trying to cope with the loss of their colleague. The staff feels defensive toward the new Chief and her tough disposition. Gates and the new interns treat a bio terrorist, who has a lethal secret that endangers them all. Neela makes a great effort to get Dubenko back on the surgery staff, and gets help from an unexpected souce.

Banfield is caught off guard when a man tries to steal her wallet; Dr. Dubenko returns to the surgery team; a family member is suspected of hurting a young gymnast; Sarah gets her tongue pierced.

Sam's time is taken up by her studies for a pharmacology exam, leaving Gates feeling neglected. A school fight results in a stabbing, with Brenner treating the victim and trying to uncover the truth behind the story. Morris has a surprise for Neela. Gates gets locked in a stairwell with a quiet young boy on Halloween night.

Dr. Banfield is irritated when Morris takes Chaz under his wing and teaches him risky medical procedures; Neela is unhappy when Dr. Banfield undermines her authority with an intern.

Dr. Banfield takes a run to clear her head but finds herself trying to rescue a three-year-old girl from drowning in a nearby lake. Gates tries to pull some strings in the ER to help his homeless war hero. Banfield is reminded of her own experience at County with Dr. Greene caring for her son as she tries to save the young three-year-old girl from certain death. Meanwhile, the interns continue to struggle to keep up in the ER.

Sam gets frustrated with Gates when he gets obsessed with finding a homeless war hero. Neela is upset at her intern after he gets the entire surgery department into a lawsuit. A husband and wife come into the ER after someone tried to burn down their home. Brenner loses his cool with a patient and it gets physical.

On Neela's last day at County, she has doubts as to whether she is making the right decision.