The book begins with the disappearance of 12-year-old Sam Markham. Sam's parents, Helen and Larry, are frantic with worry. They enlist the help of the police, but the police are unable to find any trace of Sam.
As more children disappear, the town becomes increasingly panicked. The townspeople are afraid that a serial killer is on the loose. However, Helen and Larry believe that something else is going on. They suspect that the children have been abducted by aliens.
Helen and Larry's suspicions are confirmed when they receive a visit from a man named Mr. Smith. Mr. Smith is an agent of the government, and he tells Helen and Larry that the children have been taken by aliens. Mr. Smith says that the aliens are studying the children, and he is unsure if the children will ever be returned.
Helen and Larry are devastated by this news. They refuse to give up hope, however. They start a support group for the families of the missing children, and they lobby the government to take action.
Eventually, the government agrees to take action. They launch an investigation into the alien abductions, and they send a team of scientists to the town. The scientists are able to find evidence of alien activity, and they are able to establish contact with the aliens.
The aliens agree to return the children, but they only agree to return the children if Helen and Larry agree to go with them. Helen and Larry agree, and they are taken aboard the alien spaceship.
The aliens take Helen and Larry to their home planet. They are shown a world of peace and beauty. They are also shown the children, who are being held in a stasis chamber.
The aliens tell Helen and Larry that they are studying the children because they want to learn more about humans. They say that they will eventually return the children to Earth, but they say that they need to keep the children for now.
Helen and Larry are reluctantly forced to accept this. They stay on the alien planet for several months, and they get to know the children. The children are all scared and confused, but they are also resilient. They have formed a close bond with each other, and they have learned to trust Helen and Larry.
Eventually, the aliens decide that it is time to return the children to Earth. Helen and Larry are overjoyed. They say goodbye to the children, and they return to Earth.
The children are reunited with their families, and the town of Maine is finally able to heal. Helen and Larry are heroes, and they are given a ticker-tape parade in their honor.
The book They Never Came Home is a story about hope, courage, and the power of love. It is a story that will stay with you long after you finish it.