Alien at School PDF

"Alien at School" is a popular title for graded readers aimed at English language learners, and there are a few different versions by various authors. One common version is by Michelle Brown. Assuming you're referring to this version, here's a general summary:

The story is a modern-day mystery/science fiction tale set in a high school.

The New Teachers: Strange things start happening at a high school in a small town near Boston. A comet and a constellation have crossed paths, and experts believe this could lead to alien encounters. Soon after, the students notice that some of their new teachers are behaving very oddly. Mr. Stone, the English teacher, is particularly peculiar.
Suspicion and Clues: A group of friends, including a character often named Jennifer Dale, start to become suspicious. They notice strange habits and abilities in these teachers – perhaps unusual strength, odd reactions to certain sounds or objects, or a lack of understanding of common human customs. They begin to look for clues to confirm their suspicions.
The Discovery: Through their investigations, the students eventually discover that Mr. Stone, and possibly other teachers, are indeed aliens in disguise. The discovery might involve a missing watch, strange glowing eyes, or an unexpected transformation.
The Alien's Purpose: The students learn that these aliens are on Earth for a specific reason. This could be anything from observing humanity, planning an invasion, or even seeking help for their own planet. The motive often leans towards a more benign or complex purpose rather than outright evil.
The Conflict and Resolution: The students must decide what to do with this information. They might try to expose the aliens, protect their school, or even help the aliens if their intentions are good. The climax often involves a confrontation or a plan to deal with the alien presence, leading to a resolution that reveals the aliens' true nature and the students' bravery.