The beginning of the new century was marked by a lot of trouble, but it seems that this does not apply to the main characters. Sherlock settled in Sussex, where he began to breed bees. Watson is married and is practicing medicine. Mrs. Hudson moved and set up the Holmes Museum in Baker Street. And even Inspector Lestrade retired. But the twentieth century threatens disaster. Then the threat of a diplomatic scandal unfolds, as a result of which a world war can easily begin. And what is the discovery of secret drawings of a submarine found next to the corpse of an ordinary arsenal worker? Is this connected with German intelligence and the role of Sherlock in British plans? Now you can’t envy Holmes and Watson. They have to solve several puzzles at the same time, each of which is a whole country.