Ran, Sonoko and Sera come across a corpse beside which is written the word "Die" by victim's blood.It reminds them of a 10 years old similar case, unsolved by Yasuku Kudo.

Kogoro assists the police delivering ransom money to the Nihonbashi Post Office. When arriving at the post office, Kogoro is given a briefcase with further instructions. After Kogoro falls off a boat and gets sick, Conan and Ran begin investigating, but soon...they stumble upon a body!