Sherlock, Lupin & Me: Dark Lady

Sherlock Holmes, Arsene Lupin, and Irene Adler meet for the first time in Saint-Malo in 1870. They're supposed to be on vacation, but destiny has other plans for them. Soon they're involved in a criminal vortex: a diamond necklace disappears, a dead man is found by the beach, and a hooded figure appears and disappears all over the city. The police can only grope in the dark, meaning someone else much crack this case...