By now 12-year-old Art is an old pro at spotting and stopping art heists, with two foiled thefts under his belt, so it's only fair his best friend, Camille, get a shot at doing the same. The problem is, his name's circulated among the nefarious who now seek to take advantage of his uncanny ability to track down lost and stolen artwork.

Enter Camille's father, Prof. Broderick Tinsley. She doesn't know him because he left her mom when she was a baby to seek fame and fortune, hunting down famous lost art treasures. But he contacts her and says he wants to meet her, even arranging to fly her to London. Camille brings Art along for emotional support.

But when she gets there, her father is a no-show. She tracks down her dad's flat and encounters one of her father's colleagues, Cos Masters, who leaves them alone in the house while she gets food for his parrot. The woman isn't overly concerned. Prof. Tinsley has disappeared on short notice like this before. 

Camille however is convinced her father's in danger. And she finds incontrovertible proof in his study -- the same study he Zoom video conference called with her mother to set up this meeting. She spots immediately that something in the study is off. A puppet has been moved to cover…an hourglass. 

One Art instantly recognizes as stolen from an exhibition a couple of years ago at a British art museum. Because his dad was working for it at the time. 

There's more. The kids discover the hourglass contains a hidden message. In code.

I won't say any more, or I'll ruin it. Camille is brilliant in figuring out the clues first and rescuing her father as she and Art, again, foil a historic art theft! There's even a cameo with the Queen! Enjoy!