Three concurrent surgeries at the hospital push its staff to the limits. Determined to ease the pressure, Nic requests Jude for one of the operations, making Conrad jealous. Meanwhile, Dr. Lane Hunter sets out to discredit Nic's claims, Devon struggles with a patient who has an embarrassing problem and a charitable contributor comes to the hospital wanting to donate a lot of money to Dr. Lane's oncology program.

Devon and Conrad race against the clock to save the life of a woman who is deteriorating fast from undetermined symptoms. When the patient turns out to be a hero who helps previous criminals get their lives back together, the team relies on her family of ex-cons to help diagnose and treat her. Tensions rise as Nic continues her search for evidence to incriminate Lane, but must simultaneously tend to her sister, Jessie, who is rushed into the ER. Meanwhile, York returns to the hospital with his mother, who is in need of a risky procedure, and comes face-to-face with the stone-cold Dr. AJ Austin.

When patients from the hospital's prescription drug trial start suffering life threatening side effects, Nic fears that her sister Jessie may be in danger. As a result, she and Conrad work to convince Bell that these trials are not worth the risk. Meanwhile, Mina, Austin and Kit must set aside their competitive nature and work together on a patient whose health is quickly deteriorating and Devon uses Julian as the beta tester for a product he's designed.

Devon grows concerned when a mother's complaints go unaddressed after her delivery, and pushes Bell to take drastic measures. Conrad is faced with breaking the news to Nic regarding Jessie's worsening condition. Meanwhile, The Raptor, Mina and Kit spring into action when a mother and son enter the ER with devastating injuries.

After being terminated, Conrad has difficulty figuring out his next step and distracts himself by accompanying a patient on a zero-gravity adventure. Cain puts the doctors on a commission-based pay system. Bell's company gets its big break.

Just when Derek's condition seems to be improving, a severe complication arises, causing Kitt to fear that he may be the latest victim of Cain's cover-up. When Cain's former girlfriend is admitted to the hospital for surgery, the doctors finally get a glimpse into his personal life. Meanwhile, Conrad fills in Marshall on the emergency situation facing the hospital and Mina and The Raptor work on saving the heart of a salsa dancer.

On Nic's first day back at Chastain, the man who attacked her is admitted to the ER, causing her to confront her trauma head-on. Cain, now in recovery, is self-conscious of his physical state and sets his eye on taking down Mina. The new intern both struggles and shines throughout her first day, causing Devon and Conrad to wonder if something bigger is going on.

While looking for a distraction on Halloween, Conrad treats a group of witches who send the ER into chaos. Also, Devon treats a patient who thinks he is being haunted by ghosts. Meanwhile, on the way back from his vacation, Bell picks up a hitchhiker who is not what he seems to be.

Devon sees a traveling British couple who are nervous about the cost of American health care.