Bell grows frustrated when Marshall Winthrop, Conrad's dad and new chairman of the board, requests Conrad's input in his discussions about the hospital's expenses. As Conrad and Nic work to cut costs for their patients in need, Julian Lynn, a sharp and sophisticated medical device rep, meets the staff at Chastain and inserts herself into the ongoing work of the doctors to promote her costly products. Meanwhile, Mina's relationship with Micah struggles in the wake of his healing process, and Devon is tasked with showing the eager new interns around the hospital.

Halloween at Chastain proves to be just as spooky as ever when Conrad is tasked with diagnosing a young woman admitted to the hospital with extreme night terrors. Meanwhile, Devon faces his first Halloween in the ER, Nic panics over her decision to bring her newly sober sister to Mina's epic annual Halloween party and Bell finds an interesting way to make use of his new assistant.

The surgeons are determined to shut down Quovadis after Henry Barnett almost loses his life due to a device malfunction. As Mina and Devon set out to find the truth, Bell, AJ and Conrad work to save the life of Chastain's favorite custodian, Simon. Meanwhile, one of Alec's old patients ends up in the ER, forcing him to question if he made the right choice to leave his old practice for Nic's clinic.