LIFE SUPPORT Tess Gerritsen joined the front ranks of thriller writers with her "New York Times" bestseller, "Harvest." Now she weaves utter medical authenticity into another novel of gripping suspense, as a dedicated woman doctor probes too deeply into the cause of a lethal, mystifying outbreak. The overnight ER rotation at Springer Hospital suits Dr. Toby Harper just fine -- until its calm is shattered by a man Toby admits one quiet night. Delirious and in critical condition from a possible viral infection of the brain, he barely responds to treatment...and then he disappears without a trace. But before Toby can find her missing patient, a second case occurs, revealing a chilling twist: evidence of an infection that 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: an evil, deadly design to the frightening epidemic.