Holmes was once again sitting in an armchair in his apartment on Baker Street, lost in thought as he stared at the wall in silence. His violin was on his lap, he played a few random notes every now and then, not playing a specific song.
He hadn't received any clients lately and everything was quiet, so usually the famous detective found himself bored with nothing to do...
Watson had gone on a trip with his wife, so he didn't have his friend to keep him entertained either.
He then finds himself looking towards the window, observing the activity on the street. Your attention is captured by what appears to be a man performing magic tricks on a small table, certainly with the intention of making money.
Perhaps this would be interesting...
Holmes then puts on his coat and leaves his apartment, blending into the crowd and watching the magician perform his tricks.