When a nasty flu season turns out to be masking a terribly infectious disease, Chastain must race to quarantine and diagnose infected patients. While Conrad, Nic and Alex work tirelessly on Meg (guest star Dot-Marie Jones), who was Nic’s favorite guard from her stint in prison, Devon and the others treat Sam (guest star Michael Rady), a love-sick patient with flu-like symptoms. Mina finds herself testing Quovadis medical devices in an effort to defend Dr. AJ Austin, who, feeling responsible for the death of a patient, is serving penance by staying away from the OR. Meanwhile, Conrad is prepared to take the next step with Nic, but finds that she may not be as ready.