A troubled gentleman named David ponders whether vegemite can be consumed undiluted without posing a health risk. Meanwhile his friend, a senior government official, returning from an evening, has a car accident and his passenger dies in the accident. He puts the corpse in the driver's seat, but there is a witness. To eliminate this annoying witness, he calls on his David, a physicist, who wants to make it a perfect crime by quantifying the risk taken in each of its stages. And compressing it enough to make the execution of the most improbable.