A new chamber in the Pyramid of Kheops is about to be discovered. Blake and Mortimer find that an uncommon thief, the Colonel Olrik, wants to steal the treasure that it may contain.
London has been terrorized by an enigmatic villain who informs the press in advance of his crimes. He commits daring robberies and leaves behind an "M" in a yellow circle as a signature.
Leading a gigantic army, Colonel Olrik is on the fringe of taking over the whole world . The only hope of humanity is "Swordfish", a revolutionary jet aircraft designed by Pr Mortimer.
Mortimer discovers an unknown highly radioactive matter. Going down into the depth of the earth to solve this mystery, Blake and Mortimer discover the ancient civilization of Atlantis.
Mortimer inherits the castle of his former adversary Professor Miloch. Curious as ever, he tries the machine he finds there and instantly arrives - In the prehistoric era.