Control was the word Dr Toby Harper lived by. She strove to keep her life in order, her ER in order. But no one could have been prepared for the man she admits one quiet night to the Springer Hospital. Delirious and in critical condition from a possible viral infection of the brain, he barely responds to treatment. And then he disappears without trace. The subsequent search leads Toby to a second patient with the same infection. And it reveals an unsettling twist – the infection can only be spread through direct tissue exchange. Soon Toby's on a trail that winds from a pregnant sixteen-year-old prostitute to an unexpected tragedy in her own home. Only then does she discover the unthinkable: a terrifying and deadly epidemic is about to be unleashed...