L'Alpagueur is a free-lance spy from the French secret agency. He's put on the investigation about L'epervier, a serial-killer who employs young boys to help him robbing banks before killing them.

Professor Meier has stolen the plans of his own infernal machine, the T-14, and intends to sell to the highest bidder in a transaction organized in an Avoriaz hotel belonging to "Pasha", a mob boss who acts as go between. To retrieve the famous case, the SDECEE release Peter Finshh, a professional gentleman thief, from prison to return to the plans. Peter is ordered to recover the T-14 from the possession of a group of spies in Avoriaz.

An Embassy attache and a butterfly hunter become involved in a treasure hunt between two rival gangs.