Botulism, malaria, small pox, plague. As medical producer for the highly rated morning news program "Key to America," Annabelle Murphy makes her living explaining these horrific conditions to the nation. But when someone dies inside the broadcast center with symptoms terrifyingly similar to those of the scourge on which Annabelle has just reported, panic spreads. As one death leads to another, the circumstances suggest that these may be diabolically executed murders. And when authorities lock down the broadcast center, neither victims nor murderer can escape.