Patsy, a scruffy, ragamuffin of a puppy, fills a void when Millie Lupinski's husband dies. Little does she know that the newest addition to her household will be the death of her.

Millie's death is just the first, as dog and cat owners begin to die mysteriously. Michael Dawson, chief of operations for Homeland Security's Bioterrorism Unit, and his team must work fast to determine the cause. Failure means the deaths of millions of Americans.

Chemical and biological weapons aren't anything new, but today's scientific know-how makes them a threat that could kill billions through new and...