Specialising in the reconstitution of synthetic images, the agency Imago Mundi explores the most hostile realms of the planet and tries to pierce their mysteries. It is run by Harald Haarfager, a Swedish “adventurer of the extreme,” assisted by the brilliant young French physicist Loïc Mellionnec and the young English computer star Leia Lewis…

After an accident that occurred during the laying of a cable in the depths of the Atlantic Ocean, a camera, submerged to try to find the cause of the failure, has detected a structure which seems to be architectural. Convinced that this is part of the ruins of an ancient sunken city which might be the fabled Atlantis, the Eurocom boss in charge of the project has contacted Imago Mundi. He’s prepared to finance an underwater search operation. Excited by the proposition, Harald and his two assistants set out to organize the expedition… A complex and costly technology has thus been installed near the Azores to sound the depths. But immediately accidents start to occur, which neither science, technology, nor the environment can explain. Suspected of sabotage, the petroleum company Greenoil is nonetheless soon cleared of the case. The mystery remains impenetrable — especially the strangely metallic and geometric images which the survey machine has captured in the depths. Convinced that they have been had by Eurocom and Greenoil, Harald, Loïc and Leia decide to conduct an investigation. It’s not long before they realize that the two companies are battling for a source of inestimable riches…