Kogoro, Ran and Conan join a client who has hired an assassin known as "the Fox" to kill him to a hike in the mountain to stop the assassin, who turns out to be a member of the party when a guide is killed.

A wonderland of wintertime fun becomes a stage for tragedy following the death of an actress at the peak of her career. But a suicide note and a history of poor health don't always add up to the obvious.