London's walls resound with the incredible exploits of the 'Yellow Mark.' The spectacular actions of this mysterious criminal are on the increase: holding up the Bank of England, robbing the imperial crown... No one seems able to stop him. He is so audacious that he lets the police know in advance where he will commit his crimes, each time ridiculing Scotland Yard a little more. The apparent ease with which he evades police schemes begins to worry the highest authorities of the country. The Home Office asks Captain Francis Blake to solve the mystery and discover the identity of the man who...

Captain Blake having been assassinated at Athens Airport, Olrik seems to have won the first round. A furious Mortimer swears that he'll avenge his friend. He goes on the hunt for Olrik, but information is scarce. Sheik Abdel Razek, an old man with mysterious powers, protects him against Dr. Grossgrabenstein's crew. The doctor is a devoted Egyptologist who has undertaken excavations not far from the Great Pyramid. Amidst strange events, Mortimer sometimes feels like he's losing his way in this investigation that will lead him into the darkest depths of the Great Pyramid.

Extreme weather threatens the whole of continental Europe, turning the lives of its citizens inside out. The French government calls Professor Mortimer to help solve this enigma.

When a rare necklace is stolen, Blake and Mortimer intervene to prevent a diplomatic incident.

Deep under Sao Miguel island, rumoured to be the last emerging part of Atlantis, Professor Mortimer has discovered samples of a mysterious radioactive metal. Could it be the Atlanteans' legendary orichalcum?

Captain Francis Blake, dashing head of England's MI5. Professor Philip Mortimer, world-renowned nuclear physicist. The most distinguished duo of gentleman-adventurers, battling the forces of evil and their arch nemesis Olrik around the globe, below the earth, even across time itself... The 17th adventure of Her Majesty's finest protectors!

Professor Philip Mortimer has decided to spend his holidays in Cairo with his trusty servant, Nasir. There he plans to meet an old friend, who offers him the fantastic opportunity of satisfying his passion for Egyptology - to take part in the deciphering of some recently discovered papyrus coming from mummies of the Ptolemaic age. They soon discover that one of the fragments deals with the Chamber of Horus - a fabled crypt that could contain priceless treasures...

Time for Captain Blake to enter the scene and face ... Robo-Mortimer Professor Sato, who has made incredible advances in the field of cybernetics, has been kidnapped by Olrik. A cautious man, Sato had revealed to Professor Mortimer the hiding place of the three formulae that govern his discoveries, and asked him to protect them if need be. Unfortunately, Mortimer is eventually captured as well, and Olrik makes a robotic copy of him to retrieve the formulae. Now, though, Captain Blake is coming to Japan, hell bent on finding his old friend "