William James Moriarty and Sherlock Holmes wander through the streets of rainy London. William is holding an umbrella whilst Sherlock doesn’t have one

Sherlock: Liam. He calls William by his nickname and tries to convince him to go to get shelter. William: Sherly. Not now. We have important business to deal with. In turn, William calls Sherlock by the nickname he has for him and he seems to be slightly tired from what he said.