In charge of a government mission of the first importance, Philip Mortimer goes to Scotland to study ancient volcanic lands and test the viability of a geothermal installation. He thus finds himself in the first lodges of the terrible phenomena that then affect the whole North Sea: clouds of toxic gases and a gigantic tsunami ? all caused by unexplained explosions! The victims are countless... not to mention the mummified bodies of the Doggerland (the north sea bed) that go up to the surface at the end of 10,000 burial. The Daily Mail title: "What is going on in the North Sea? The impotent Yard!" It is time that Francis Blake joined Mortimer! While they are in the midst of underwater exploration, their submersible is damaged. They are trapped by characters whom they know only too well: Olrik, of course, but also Magon, the phulacontarque of the Atlantes! Taking advantage of an energy crisis that affects (also) the Nova-Atlantis, they will not be able to get back to the North, and finally destroy his life-saving mission without having found a great chance to escape from the North. He will not be able to get back to get back to the North.