Julianna Guill

When Lily and Marshall realize that Robin and Barney are the perfect double-date friends, they try too hard to impress and come on too strong, forcing Barney and Robin to try to break up with them.

After a series of strangulations in Boston, the BAU looks for an UnSub who likes to keep mementos of the victims, and the team wonders if a common link to the casualties could lead them to the culprit.

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.

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.