Dasha Bestuzheva was looking forward to her trip to London, the hometown of Sherlock Holmes. And now, finally, she is in England! She even had the opportunity to meet Sir Arthur Conan Doyle... But Dasha didn’t have to enjoy the sights and pleasant company for long. She again found herself involved in the investigation of a detective story. This time, Count Alexei Nikitin, an old friend of the Bestuzhev family, was killed. A precious necklace that previously belonged to Empress Catherine II was stolen from his bedroom. The famous London police have clearly arrested the wrong man. But it seems that Dasha can help the innocent and understand the true cause of events. True, to do this she will have to find the mastermind of the crime, whose traces lead to France...