A suspected murder, a jewel heist, and a missing body have Conan and the Junior Detective League working every angle to crack the case. Will Conan be able to put the clues together in time?

When Kogoro and Ran attend a cooking class and the teacher is stabbed in the back with a very thin weapon during a blackout, Conan realizes that the killer is one of her students and the weapon is hidden somewhere in the classroom.