In the quiet halls of Camden Institute of Technology, a new administrator named Mary Swallow believes she’s starting a peaceful academic job—but something sinister is already moving beneath the surface. When mysterious shipments of mice, fleas, and sealed containers begin leaving the university for cities across the world, a warehouse worker’s discovery sparks a terrifying investigation. Soon, millions begin dying in global cities from what looks like the flu… until Mary uncovers the horrifying truth hidden behind two letters: “Y.P.”—the deadly bacterium Yersinia Pestis, the same plague that wiped out millions in the Middle Ages. As secret agents, shadowy pharmaceutical companies, and global conspiracies collide, the world teeters on the edge of a modern bubonic apocalypse unleashed through subway systems. With time running out and millions of lives at stake, Mary must expose the truth before the deadliest biological terror attack in history spreads beyond control. This year, the smallest creatures on Earth carry the deadliest secret… because sometimes it’s the little things that kill you.