Jimmy Kudo, the son of a world-renowned mystery writer, is a high school detective who has cracked the most baffling of cases. One day while on a date with his childhood friend Rachel Moore, Jimmy observes a pair of men in black involved in some shady business. The men capture Jimmy and give him a poisonous substance to rub out their witness. But instead of killing him, it turns him into a little kid! Jimmy takes on the pseudonym Conan Edogawa and continues to solve all the difficult cases that come his way. All the while, he's looking for the men in black and the mysterious organization they're with in order to find a cure for his miniature malady.

Conan stumbles upon his creepiest mystery yet, complete with a haunted house, a spooky pair of twins, and...a giant spider? Are Conan and his friends really under attack by restless spirits, or was this web of terror spun by human hands? Good thing Harley Hartwell's there to help with the case! Then the Junior Detective League goes camping--only to run afoul of a gang of crooks, a labyrinth of caves, and a whole bunch of angry bats!