In "My Teacher Flunked the Planet" by Bruce Coville, Peter Thompson's alien teacher, Mr. Smith, returns to Earth to warn Peter and his classmates of an impending alien invasion. But when Peter discovers that the aliens are actually peaceful and have come to Earth to help, he must team up with his teacher and an unlikely ally to save the aliens from the military forces that have been sent to attack them. As they race against time to prevent a disastrous war between humans and aliens, Peter learns valuable lessons about trust, loyalty, and the true nature of friendship. With its engaging storyline, well-developed characters, and themes of acceptance and understanding, "My Teacher Flunked the Planet" is a fun and thought-provoking read for young adults.