THEY THOUGHT THEY'D ALREADY FACED THEIR TOUGHEST FIGHT.

But there's no relaxing for the reunited Zeroes.

These six teens with unique abilities have taken on bank robbers, drug dealers, and mobsters. Now they're trying to lie low so they can get their new illegal nightclub off the ground.

But the quiet doesn't last long when two strangers come to town, bringing with them a whole different kind of crowd-based chaos. And hot on their tails is a power even more dangerous and sinister.

Up against these new enemies, every Zero is under threat. Mob is crippled by the killing-crowd buzz--is she really evil at her core? Flicker is forced to watch the worst things a crowd can do. Crash's conscience--and her heart--get a workout. Anon and Scam must both put family loyalties on the line for the sake of survival. And Bellwether's glorious-leader mojo deserts him.

Who's left to lead the Zeroes into battle against a new, murderous enemy?

This description comes from the publisher. Swarm is the second book of the Zeroes Trilogy, the first of which is Zeroes.