Found
Margaret Haddix
 In the beginning of the story Jonah and his friend Chip Winston, who also learns that he is adopted, receive letters from an unknown person. The letters say “You are one of the missing” and “Beware! They are coming to get you”. At first they take it as some kind of joke but soon to wonder more and more about who are their birth parents and why they got these letters. They decide that the best way to figure out is to go into Chip’s parent's safe. There they find a phone number to an FBI agent named James Reardon. Soon Jonah asks his parents if they can call the adoption agency and ask who his birth parents really are. They only tell his dad to contact the FBI to talk to James Reardon. Jonah, his parents, and his sister Katherine meet James Reardon. Right before the meet, a janitor gives Jonah a bottle of Mountain Dew. When they finally meet with James Reardon, he tells them Jonah was illegally adopted from a foreign country and might be deported. He refuses to tell them the country's name, though. When Jonah goes to the bathroom to throw up thanks to the Mountain Dew, another, younger janitor appears out of nowhere in the bathroom and tells him a file would appear on the desk by the time he got back. He tells Jonah to memorize as many names as possible. Back in the room, he distracts the adults while Katherine takes pictures of the documents. It turns out to be the addresses and phone numbers of 36 teenagers, including Chip and Jonah. It also includes the names of several adults, including a woman named Angela DuPre. Chip and Katherine begin calling the numbers. The adults all hung up. Most of the kids turn out to live in the vicinity of Chip and Jonah. After a while they receive a letter from Angela DuPre, telling them to meet her at the library to talk about the things that are happening and get more information. At the library, Angela DuPre tells them that time travelers exist and that she had been researching. She tells them that she used to work at an airport, until an airplane, full of babies, appeared out of nowhere. After the babies were removed, the plane disappeared. She speculates that the babies on the plane were originally adults who were turned into babies by time traveling. Then a man breaks into the room and is promptly tackled by the "janitor" from the FBI who talked to Jonah in the bathroom. Chip, Jonah, and Katherine escape through a window, but Angela stays behind for more information. Later, when they're leaving the library, they see Angela, who disappears into thin air. When they get home, they find out the lists of names was deleted from Chip's computer. Shortly afterwards, Jonah's mom receives a flyer in the mail advertising an adoption conference for teen adoptees and their parents. Jonah persuades his parents to let him bring Katherine along, too. At the conference, all the adoptees are divided into two groups, with Jonah, Chip, and all the kids on the list in one group, and everyone else in another. Katherine pretends to be a girl named Daniella McCarthy to get into Jonah's group. The kids are led to a cave in the woods by two men name Gary and Mr. Hodge. Then the cave is transported to a place called a time hollow. The "janitor" from the FBI, whom Jonah, Chip, and Katherine have nicknamed JB, appears and attacks Gary and Mr. Hodge. Soon Angela arrives too. They find out that Gary and Hodge work for an organization called Interchronological Rescue, an organization dedicated to rescuing children from history, such as toddlers trapped in burning houses and people left for dead during the Bubonic Plague; taking them to the distant future; turning them into babies; and putting them up for adoption. The organization got greedy, however, and they started taking famous babies whose disappearances were noticed. Finally, when they were flying to the future with a load of babies, JB chased after the plane and caused it to crash in the twenty-first century. Gary and Hodge want to turn all the kids into babies and take them to the future, and JB wants to send them all back to die. Finally, JB sends Chip and another boy named Alex back to the fifteenth century , but Jonah and Katherine grab Chip's arms right before he disappears and find themselves falling backwards through time. On the way, Jonah manages to convince JB to let him and Katherine help Chip and Alex repair time so everyone can go home to the twenty-first century.