A renowned physicist and the head of MI5 battle threats to the Empire and solve extraordinary mysteries across the globe. The 31st adventure of Blake & Mortimer, the most distinguished duo of gentlemen-adventurers!

Strange events are plaguing the North Sea: animals dying in large groups, unexplained light phenomena, abnormal seismic activity, even several ships found with their crew inexplicably dead … When a tsunami strikes the eastern coast of Scotland before Mortimer’s very eyes, things become clear: something is happening below the surface. The two heroes will have to face a dark threat coming from an ancient civilisation that they believed had departed the Earth.