"Someone's stealing the squirrel's nuts, and it's up to Detective Gordon to catch the thief. Unfortunately, solving this crime means standing in the snow and waiting for a long time... If only he had an assistant--someone small, fast, and clever--to help solve this terrible case. Then Detective Gordon would be able to go back to doing what he's best at: thinking, eating cakes, drinking tea, and stamping important papers" -- Page [4] of cover.

The first story in this volume has Conan and the gang solving a mystery on a cruise ship. Then, a doctor has been getting a million yen a month, accompanied by toys for his child. Unable to figure out who's sending him these gifts, he turns to Conan and co. for help.

"And then there were two: At long last, Conan has located the scientist responsible for the formula that turned him into a kid. Trouble is, she's taken the formula herself and she can't change back! Together, Conan and the diminutive doctor track down a floppy disk that may contain the secret to curing their condition, only to find the former owner crushed under a fallen bookshelf. Can they crack both the locked-room mystery and the locked disk?"--Cover...

When High School detective and prodigy, Jimmy Kudo involves himself too far into a mystery of two men wearing black, he ends up being turned into a tiny preschooler with a high schooler's mind. To cover up his flaw and to keep his friends safe, Jimmy must pretend to be the preschooler he turned into and stay at his best friend, Rachel's house under the name "Conan Edogawa."

Surely the Junior Detective League can't get into any trouble at an afternoon monster movie. But when a man in the audience dies, Conan and Anita realize that the real monster isn't the one on the screen. Then, an ocean liner trip turns sour when a suspicious explosion--and then the usual dead body--sends Conan and Harley on a hunt for the killer.

Conan isn't sure whether to trust Jodie Saintemillion, the American high school teacher whose ditzy blonde exterior conceals a calculating mind. When a bus is hijacked by desperate criminals, Ms. Saintemillion turns out to be cannier than Conan ever imagined, revealing a head for crime solving and a body for kicking butt. But Anita can't help noticing that wherever Conan's beautiful, mysterious new ally goes, the Syndicate never seems to be far behind....

Twelve mystery cases for readers to solve, with solutions provided in the back of the book.

It's no great surprise to find a corpse in Kashiragami Forest; the supposedly cursed forest is a popular destination for would-be suicides. But the latest suicide case has the local police suspecting foul play. Then a tall, dark man with a mustache hangs himself himself at a local hotel--after claiming to be Detective Moore! Are the "suicides" really something more sinister? And if so, is the killer laying a trap for Conan and the real Richard Moore?...

When Doc Agasa takes the Junior Detective League to an old abandoned mansion for a treasure hunt, the treasure they end up discovering is counterfeit U.S. bills--and someone else is after it, too! Then, Richard is consulted on a sleuthing video game; and while there, Conan runs into a member of the Syndicate. But before he can find out more, an explosion kills the man, and even the investigation ends with Conan's hopes of finding more about the organization...

While playing hide and seek, Amy discovers a chopped-off head. Will Conan and the Junior Detective League be able to save her from a serial murderer? And when Richard Moore attends a reunion of his college friends, one of the ends up shot, gun in hand. Was it suicide? Or murder? Later, Conan, Richard, and Rachel attend the birthday party of a wealthy financier's daughter; but Conan's detective skills are put to the test when the birthday girl goes...