A tin box walled up in the catacombs of Paris... The police find in it a gold pendant, an antique stethoscope, a military cross, a tibia and... a skull. An examination establishes that the skull belongs to a famous politician who disappeared without a trace ten years ago. But... why did the killer put it in box everything else? Enzo McLeod, a long-retired British criminologist who is able to solve even the most sophisticated crime, takes on the investigation...