Bell grows frustrated when Conrad's dad and new chairman of the board requests Conrad's input in his discussions about hospital expenses. A sharp and sophisticated medical device representative tries to promote her costly products.
Conrad must diagnose a young woman who gets admitted after having extreme night terrors. Devon faces his first Halloween in the emergency room. Nic panics over her decision to bring her newly sober sister to Mina's epic annual Halloween party.
The surgeons are determined to shut down Quovadis after Henry Barnett almost loses his life due to a device malfunction. Meanwhile, Bell, AJ and Conrad work to save the life of Chastain's favourite custodian.
MacGyver finds himself tasked with fixing a sabotaged train to protect an informant who has evidence that her boss has started selling weapons to enemies of the US.