While navigating the fallout from Katie's secret, Amy treats a critically ill patient with a dark one of her own. As Gina and Jake evaluate a world-class poker player, searching for the source of what may be a mental disorder, Jake is forced to hide the truth from Amy about Rachel's health scare. Sonya and TJ investigate their theory behind Joan's frequent absences. And Richard returns with a trick up his sleeve.

After a tragic accident, one of Joan's oldest friends is rushed to Minneapolis to be treated by her, forcing Amy to confront her about her illness; Richard and TJ find themselves at odds when they treat a tech bro who thrives on pushing boundaries.