Set in the summer of 2019, the story follows Violet Wilson, a high school student determined to revive her school's journalism club. Her plans take a bizarre turn when the kids hike leads to a series of strange events, from the discovery of a crashed flying saucer to Willys’ eating what appears to be an alien sandwich.

This seemingly simple act unleashes a series of chaotic events involving the FBI, led by the quirky Agents Orange and Goldblatt, and eventually, the President himself. The aliens, giant sandwich-like beings called Goobexes, demand the return of their missing offspring, Goobex 3. The ensuing search for the alien and the mysterious Dr. Harrison culminates in a tense standoff with the military.

The book’s quirky characters, including the fact-seeking Violet, her supportive best friend Pamela, and the accidentally-snacking Willys. The Goobexes, as alien beings shaped like sandwiches, add a unique and humorous touch. Beyond the laughs, the story explores important themes of critical thinking, cooperation, and the importance of peace. The temporal anomaly that resolves the central conflict adds a clever twist.

While the plot is lighthearted, it doesn't shy away from subtle social commentary, particularly regarding the importance of questioning and understanding the world. The book's plot, combined with its relatable high school setting and engaging characters, makes it a fun and thought-provoking read. "Peanut Butter and Jelly Sandwiches From Outer Space!" is a reminder that even the most ordinary events can lead to extraordinary adventures, and that even a peanut butter and jelly sandwich can play a role in saving the world.