Dr. Sydney McKnight, a young physician battling the deadliest influenza pandemic of all time, joins forces with Dr. Casper Jones, an odd new research virologist whose arrival coincides with the virus's advent, and whose presence raises more questions than answers.
As scientists around the world search for an explanation for the virus's high mortality rate, Sydney's distrust of Casper grows, especially after she discovers him injecting an unidentified substance into her patient. Despite a heavy patient load, rebuttals from her boss, and an increasingly strained relationship with her boyfriend, Sydney is determined to learn the truth.
But what she finds will plunge her into danger and change her life forever...