The science-fiction novel “The Maracot Deep” became Arthur Conan Doyle’s last major work. The novel describes an expedition led by Professor Maracot, who with his companions descends into a deep-water trench in the Atlantic Ocean, where he discovers an ancient city of Atlantis. The researchers become acquainted with the local inhabitants—their culture and way of life—as well as with the exciting and unexplored world of the ocean’s flora and fauna.