Your characters must include a disguised scientist, a paranoid detective, and a reckless taco salesman.
One must be 70 or older. Another must be 13 or younger. These characters must work together to meet some end.
The Three? by Lexi Anders
The Taco is the Job by Natasha Blade
Termites, Teacher and Taco Sauce by Hannah Christensen
Crazy Cases by ED Nobody