In Zeroes we were introduced to a group of teens with unusual, mostly subtle superpowers who find themselves in an increasing amount of trouble with both drug dealers and the police, using the very powers that got them into trouble in the first place to get them out again. I liked the novel a lot, so when I found out about the sequel, I was very excited.
My excitement was not misplaced. Like Zeroes, Swarm gets into the action quickly, but unlike the first book, we don't need to get to know the main characters, so the plot moves even faster, the tension ratcheted up. It's also nice to see the main characters all more comfortable with their powers and better at working together as a team. Which sets everything up for even more tension and danger as the Zeroes encounter other teens with strange powers, powers that make them doubt their own abilities and throws a wrench in their team dynamic. While Zeroes focuses on superpowered teens dealing with street level crime, the sequel gives them a real super villain, one with a personality and power that is truly disturbing and scary. At the same time, the Zeroes are forced to deal with some of the fallout from the first book. Nothing is ever easy when you're a teenager, and that's doubly true when you have strange powers you're still learning to understand.
If I was excited for this sequel, I'm even more excited for the next book in the series, thanks to the Empire Strike Back-like ending that left me worried about the future of these characters I've come to care about. And I want to see more of the weirdness that is the superpowered world of the Zeroes.