Death by Dinosaur — Jacqueline Guest

Fourteen-year-old Sam Stellar and her cousin Paige have decided to spend the summer working at the Royal Tyrrell Museum. Paige, a computer whiz, works in the IT department (and has one eye on the adorable assistant helping out in the museum), while Sam, an aspiring detective, is convinced there's a theft about to happen.

Sure enough, a piece from a dinosaur fossil goes missing. Determined to solve the crime, Sam drags Paige along as her unwilling accomplice.

As Sam closes in on the truth, things get ugly, and she finds herself trapped inside the museum, with no way out.