In The Mystery of the Mona Lisa, Jack is sent to the Louvre Museum in Paris to track down the theft of the world's most beloved painting. He must match wits with a seemingly invisible mastermind in order to stop Leonardo's masterpiece from slipping into the criminal underground forever. Can Jack's Hypo-Disk overpower a glove that shoots laser beams from its fingertips? Jack's adventures in the city of light demonstrate once again that when it comes to outsmarting the baddies, Jack is the go-to agent with endless tricks up his sleeve."

In one of his most daring exploits, Jack goes down under -- literally -- to investigate the disappearance of a diver off the Great Barrier Reef of Australia. Using everything in his backpack arsenal from anti-puke pills to a morphing suit, an egg-shaped submarine to Disappearing Milk, he exposes a deadly nest of pirates raiding a shipwreck site. Jack has to thwart their schemes, evade their attempts on his life, and escape the primordial hunger of three deadly species: a Komodo dragon, a set of sharks, and the most poisonous predators in the reef, the Irukandji jellyfish. Can he save the...

In The Escape of the Deadly Dinosaur, Jack zooms to the city that never sleeps to try to solve the mystery of the missing Allosaurus toe. Starting at the Natural History Museum, Jack's detection takes him to a competitive grade-schooler determined to win the science fair with his experiment crossing his own dog with the DNA from the bone of a dangerous, carnivorous dinosaur. Soon the gargantuan creature is terrorizing New Yorkers and Jack must stop him before he devours the animals in the Central Park zoo

In this thrilling and educational adventure series, nine-year-old secret agent Jack Stalwart travels to the farthest ends of the earth to solve international crimes and bring home his long-lost brother, Max.