In a post-plague world where humans, animals, and plants have suffered, a colony of survivors has gathered in a fortified former-luxury condominium complex they call "The Park". These remnants of humanity are inextricably bound to their domestic cats from which Dose (a temporary plague vaccine) is derived. A forager army is heading toward The Park. The Park people must prepare to defend themselves and all they have worked for. They have made a discovery: not all cats are created equal. While regular Dose staves off plague symptoms, the dose derived from Simon (The Park's only Siamese cat) can be refined into SHAT, a super-dose that rejuvenates the growth of plant life. . . and which also may hold the secret to a permanent plague-cure. Problem: Simon is a neuter. If he should die, so, too, dies humanity's hope for survival. Enter Sasha, a purebred female Balinese of breeding age that also produces SHAT. With the increasing militarization in The Park (and sky-rocketing tension), Sasha's humans want to leave, taking their cat with them. But The Park people won't let them go. . . .