The Gondwana Shrine is the eighteenth Blake and Mortimer comic book in the series. The book was published in France and Belgium on March 28, 2008. Plot In Tanganyika, Professor Heidegang discovers in the lake of the Ngorongoro crater a secret entrance leading to a sort of sanctuary. He seizes a ring as proof of his discovery but menacing men appear and he flees, wounded in the thigh. In London, professor Philip Mortimer, fatigued and suffering from memory problems since his experience in the sarcophagi of Açoka, is recommended by his doctor to rest. Nastasia Wardynska, of the CSIR, brings the results of the analysis of the rock he brought back from Antarctica: it is a 350 million year old gold and diamond rock on which is engraved enigmatic signs that would prove the existence of a civilization at that time. At the Centaur Club, Mortimer shares his discoveries with his friend Captain Francis Blake, who had to go to France to meet Professor Labrousse, their French meteorologist friend, about his invention, Subglacior II. Mortimer goes to the Daily Mail archives where Mr Stone shows him an article on Dr. Heidegang that says paleontologists Mr and Mrs Leaky had been found delusional and clasping in their hands a ring engraved with the same enigmatic signs. On his return home, Mortimer immerses himself in reading his memories and discovers that the writer and amateur archaeologist Sarah Summertown, with whom he had an adventure in his youth, is a friend of the Leakys. In the archives of the Daily Mail, a mysterious man manages to consult the article on Prof. Heidegang by posing as Mortimer's assistant to Mr Stone. The next day, Mortimer goes to Sarah Summertown for the first time in many years. After having told each other their lives, Sarah agrees to help Mortimer on the condition that she accompany him on her adventure, and later Nastasia imposes her presence on him too. At the London airport, Mortimer, Sarah and Nastasia board for Nairobi under the surveillance of the mysterious man. In the plane, Sarah talks to them of artifacts engraved with the same enigmatic signs found in the four corners of the world, which could indicate the existence of a civilization at the time of the unique continent of Gondwana. In London, the mysterious man enters Blake's house during the night and threatens the captain with a pistol. He