A professional gang break into the vaults of Jonkhere Private Bank in Brussels and target 66 safety deposit boxes, stealing only certain valuables and documents. The owners of the targeted boxes are all prominent figures from the top layer of Belgian society and determined to keep their secrets, but Inspector Paul Gerardi of the Belgian Federal Police gets wind of the robbery and wonders why the crime has not been reported.

On witnessing the assassination of Urbain and hearing of the death of his informant Strubbe, Geradi now knows his suspicions of a major unreported bank robbery are correct, but he is perturbed to realise that his house is under surveillance and that his official enquiries are being thwarted.