Abby is distressed when her mother interferes with Eric's treatment at a psychiatric hospital. Pratt treats a frightened young girl who has been injured in an auto accident and desperately wants to hide a secret. An unhappy Luka forms an unlikely bond with a lonely elderly woman who makes him a surprising offer. Chen is overcome with upsetting memories when a baby is abandoned in the emergency room. Pratt takes action after Leon is fired from his menial job.

Carter sticks up for Neela when the other attendings doubt her future in the ER. Neela caves to the pressure and accidentally gives a patient the wrong medication. Gallant takes the blame for her though. Sam and Luka try to plan Alex's birthday party. Frank visits on his way to therapy. Chen's home nurse quits after her dad behaves poorly.

Neela is still struggling with her decision not to continue becoming a doctor. We discover that Ray is in a band. Kovac and Sam are amoureux, but where does that leave them?

Jules 'Ruby' Rubadoux is back in the ER. He's still angry with Carter about the death of his wife.

The rainy night brings in diverse patients including a mother involved in a car accident with her baby, a man with a satisfaction facilitator, and a comatose patient who suddenly wakes up. Also, Sam steps up to Eve and her strict ways and Jerry gets struck by lightening!

Dr. Nate Lennox, a former professor with ALS, is brought in as the progression of his disease is chronicled through his own flashbacks as he is treated by each of the doctors at one point. As Lennox wants to give up, Abby fights to convince him to keep on fighting.

It's time for changes at the ER when Anspaugh makes an unpopular decision. Abby has old demons to fight with, which distance her from friends and family. Even Luka seems to be at a loss to help Abby. Love is in the air when a secret romance blooms between two doctors.

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.

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.