The boy was one of the mutant kids whom the Flock encountered in Florida during School's Out - Forever.
While the Flock is camping in a swamp, Angel senses people approaching. Two small children emerge from the woods slowly. They were apparently attracted by the smell of the Flock’s food. Max gives them food and Fang gives them water. After eating ravenously, the kids finally slow down and become drowsy.
The boy explains that he and the girl were kidnapped from different places in south Jersey, and that they are not related. They escaped a couple of times and once made it to a police station, but were quickly recaptured. After the girl lies down to rest, he does so as well. Fang asks who kidnapped them, and the boy says that they were doctors in white coats. He and the girl immediately fall asleep, leaving the Flock horrified.
Angel senses that their thoughts are weird “flashes of grown-ups and darkness and water,” indicating that they really were experimented on by the School. However, they are neither Erasers nor normal kids, leaving Angel unsure.
The girl gets up, believing that everyone is asleep, and shakes him awake. He wakes up immediately tense, “the way kids are when waking up often = bad news.” The two of them slip into the woods so quietly that not even Iggy notices. Both kids look around to make sure they’re not being followed, but Max is able to track them silently.
She catches them communicating with the school. When she grabs the girl, both kids immediately give up. The boy drops to his knees and cries openly.
He mentions that nobody fed them for two days, in order to motivate them to find the Flock. He and the girl are left lying in the swamp when the Flock flies away. Their further fate is unknown.
Like the girl, he is very small and bony, with big eyes, and filthy. Max indicates that both of them look like normal humans.