Mori is in the hospital after injuring his ankle. While there, he witnesses a shadow of a murder. After causing an uproar three times and finding the place where the murder took place was an empty room, the murder occurs on the fourth time. Conan figures out that light is being reflected to that room and that the the first three times were in a different room while the fourth one occurred in the room Mori presumed. The culprit has an alibi of talking to the nurse in another room at the time of the murder. Mori is desperate to go into the Sleeping Kogoro phase to prove his innocence and happily exclaims it's coming when Conan secretly shoots a tranquilizer dart. Conan disproves the culprits alibi and proves Mori to be innocent.

Ran, Sonoko, and Conan spend the night at a Mountain Villa with their former teacher, Akiko Yonehara. The Mountain Villa has a checkered past, as a massacre occurred three years prior and a mysterious journalist warns it will occur again! It’s up to Conan to find the clues before another massacre happens.

Conan is troubled how a piece of rope disappeared. He realizes that the person has killed two people on the same night. By giving Ran clues to reveal the secret by a shocking culprit is revealed!