After losing the geography bee when answering a question about Brazil, the boys get a mission from the Global Protection Force. One of their agents in the rain forest hasn't been heard from, so while the boys are supposed to be studying, they are whisked off with GPF technology to the wilds of Brazil. Luckily, they know all about the climate and indigenous animals. When they come across Pedro the Pistol, who has a gang of men looking for gold, they suspect that the missing agent is in his hands. They find out they are correct after Pedro captures them as well, and threatens to put all three agents on a boat going down the river. Luckily, Max and Jack are able to use their gadgets and know-how and save the day, getting home before their parents even know they are gone.

These books remind me very strongly of the Magic Treehouse Books-- lots of adventures, fun facts about different nonfiction topics, very cool gadgets that we should all have as a matter of course. They are a bit formulaic (there's always going to be a bad guy that causes Jack and Max to head off on an adventure to save the day), but that's something that appeals very strongly to the target demographic, which is 1st-4th graders. Piles of these books make great summer reading, and when paired with The Secret Agent Training Manual, you know that readers will be occupied making disappearing ink out of all of your lemon juice and leaving lots of coded notes about what they want for supper. Great fun!