Most good stories start with a fundamental list of ingredients: the initial situation, conflict, complication, climax, suspense, denouement, and conclusion. Great writers sometimes shake up the recipe and add some spice.
Exposition
The Nest
The book opens up by introducing us to Max—the main character—and her motley crew of avian-human hybrid friends. The exposition shows readers how the hybrid children live at their house, and how they're constantly on the run from nefarious scientists and Erasers (wolf-human hybrids), providing valuable background information so that the rest of the story isn't too discombobulating. It also sets up tension: The children aren't allowed to live in peace—not if the Erasers and the scientists from the School have anything to say about it, anyway.
Rising Action
Seeking an Angel
Things get a bit hairy when the Erasers find out where the flock is living and swoop down to kidnap the youngest flock member, Angel. She's the one with the craziest powers, too, since she can actually read people's minds. Because the flock members see each other as family and not just as buddies, they all agree that they have to find Angel—even if it means setting foot into the School. They fly to the School and bust Angel out, although it requires a bit of elbow grease and even some grand theft auto.
Climax
New York, New York
After the gang leaves the School, Angel drops a huge bomb on them: While she was being held hostage at the School, she was able to glean from reading some scientists' minds that there is a place in New York City that has more information on all of the flock members—and their biological families. Whoa.
Since the avian-human hybrid kids have never grown up with a family, they're intrigued and feel like they have to go check this out. They all fly off to New York City, but on the trip Max starts having these crazy brain attacks where random visions flash in her head and a voice starts talking to her, leading her towards the Institute—the place where they can find the info Angel knows exists. It's more than a little bizarre and creepy, but more importantly, from this moment forward, nothing can ever be the same. That voice just won't leave Max be.
Falling Action
The Hunt Is On
In the Big Apple, the kids are busy trying to hunt down the Institute while the Erasers are busy hunting down the kids. Good times. There are several altercations and close calls, but eventually the voice inside Max's head (which keeps insisting that Max is destined to save the world) leads them to the basement of an office building, where they find all of the School's files stored.
They grab the files, but in the process, they discover that a bunch of other hybrids are being kept in cages there. Obviously, they can't leave the other hybrid kids cooped up like that, so Max makes the decision to release them all. With the information about their families in hand, though, things are starting to wind down for Max and the flock.
Resolution
Homeward Bound
In the end, the flock manages to escape the Erasers with all of their personal information, even though Max kills Ari (one of the Erasers who may or may not be her biological brother) in the process. All of the kids have information on their biological parents except for Max, who tries not to feel too disappointed. They discover that most of their biological families are grouped around Washington D.C. (leading to the idea that this whole hybrid project might be a government operation), and so Max makes the executive decision that they'll go there first.
Does the book wrap up all the loose threads? Nope—but so it goes in a series.