When a group of Austrian cavers exploring a network of abandoned military tunnels in the Italian Alps come across human remains at the bottom of a deep shaft, everyone assumes the death was accidental - until the still unidentified body is stolen from the morgue and the Defence Ministry puts a news blackout on the case. And is the recent car bombing in Campione D'Italia, a tiny tax haven surrounded on all sides by Switzerland, somehow related? The whole affair has the whiff of political intrigue. That's enough to interest Aurelio Zen's boss at the interior Ministry, who wants to know who is hiding what from whom and why.

The search for the truth leads Zen back into the murky history of post-war Italy and obscure corners of modern-day society to uncover the truth about a crime that everyone had forgotten.