It's sleepover night at a science museum in Boston. Dink, Josh, and Ruth Rose can't wait to settle their sleeping bags near the museum's colossal fossil--a giant Spinosaurus skeleton--and tour the exhibits long after closing time. But after they fall asleep, they wake to a terrible crash Is the dinosaur fossil damaged? Or is there another big problem at the science museum?

Help Dink, Josh, and Ruth Rose solve mysteries...