Benson and Stabler race against the clock as they use a gamer's avatar to track down her kidnapper before he hurts her.
Iris welcomes an enigmatic ally to their community, while Hope questions the visitor's motives; a message upends the sisters' world view, forcing them to decide between the safety of their home and the uncertainty of the world beyond.
Dr Connor Rhodes must deal with his past when he takes care of a family friend; Dr Halstead struggles with a surgery that could impact a young musician's hearing.
Dr Halstead treats a former high school classmate. Doctors Manning and Charles try to treat a young patient who refuses to take medication.
An old friend's heart problems reveal a bigger issue than anticipated; Devon treats a suicidal woman who he thinks might be a good candidate for deep brain stimulation; Billie and Trevor have an emotional reunion.