Darwin Theatre is in lockdown, with Joseph and Jac trapped mid-operation. The race is on to discover the cause of the contamination before the whole team is wiped out. Annalese is unable to control her feelings of guilt, fleeing from a major operation and thus arousing Connie's suspicions. What is going on? Mark is frustrated when Daisha doesn't seem to be focusing on her work or her child. Does she have post-natal depression? A surprise visitor may be able to help her.