YA Mystery and Thriller writing prompts

In a small lakeside town, during the annual summer festival, a legendary old watch said to belong to the town's founder goes missing. The protagonist and their friends discover a cryptic map tucked inside an old library book, launching them into a thrilling race to find the watch before it's lost forever.

The night before a regional science fair, the groundbreaking project of a brilliant teen inventor is mysteriously sabotaged. Teaming up with a rival competitor, they must navigate a maze of clues and suspects within their own school to find the saboteur and restore the damaged invention before it's too late.

When a notorious graffiti artist who targets only the most secure public buildings suddenly stops, the community breathes a sigh of relief. That is, until a teen discovers that each tagged location was a piece of a larger, sinister plan, and the final target might just be their own high school.

Write a story about a group of high school friends who discover an old, unopened letter in a bottle while cleaning the beach for their community service project. The contents of the letter lead them on a wild adventure to solve a decades-old missing person’s case.

Write a tale about two siblings who find an old camera at a yard sale. When they develop the film still inside, they find pictures of people they don't know in front of their current house, dated 50 years earlier. Each photo is a clue that leads them closer to uncovering a long-hidden family secret.

Create a story where your main character, a teenage amateur coder, receives strange, coded messages on their computer. As they begin to decode the messages, they realize they are being drawn into an online game with real-world stakes, involving a secret society and hidden treasures.

Two teenagers camping in the deep woods stumble upon an old, abandoned campsite with items scattered everywhere, but no signs of the former campers. When they decide to investigate further, they find a riddled diary that leads them on a mysterious treasure hunt—the stakes get higher as they realize they are not the only ones searching.

While working a summer job at a local museum, a group of teenagers stumbles upon a series of hidden messages scrawled in ancient languages on some of the exhibits. As they decode the messages, they uncover a centuries-old secret that some prominent town figures would do anything to keep buried.

At the annual school fair, the fortune teller's tent is the main attraction. But when your character and their best friend get their fortunes told, they're warned about a looming danger within the school's walls. It's up to them to uncover the mystery without tipping off the wrong person about what they know.

Imagine your character receives a mysterious letter that contains only a single clue to their missing sibling's whereabouts. As they follow the trail, each clue delves deeper not only into hidden places in their town but also the secrets their family has buried for years.