Conan, Ran and Kogoro go on a rented car to hot spring (onsen), and receive a call by cell phone from Inspector Megure.

Megure informs Ran who happens to have a cell phone that a bomb was set up in the car.

According to Megure, this bomb is set up in a way that its explosive device is activated when the car travels 10 kilometers. Unfortunately, the time Megure called them, the car had already traveled 10 kilometers.

Megure instructs them to continue driving the car because that explosive device was set up in a way that it would explode when the speed of the car goes blow 20 Kilometers…