Carbon 12

Someone is stealing diamonds, thousands of carets and returning most of them for a very small finder’s fee. No diamond merchants are pressing charges. A huge purchase was made and then 80% were sold at a loss but the rest were kept. Inspector Strong in a Chief’s meeting noted, “Someone is inspecting the diamonds and maybe keeping what they want.” Robbery is all over this, but it leads no place.
Someone tries to recycle an empty whiskey bottle. The bottle owner stabs several people trying to get his bottle back and is killed in self-defense. The Inspector closes the case. The Inspector goes down to see the bottle. He finds a three-caret clear diamond in it. The diamond has no marks on it.
In the Outback, a complete city is built to dig for diamonds. Almost 50% of these they keep. The rest they sell. The mine runs out quickly, and they leave everything there.
Someone is trying to build a super-fast computer. They have invested several hundreds of millions in the project. The first test is in red China, and for what purpose? Can they predict weather? If so at what cost?