On a sound stage inside the cavernous building, time travels back to 1891 as two men in Victorian garb occupy a second-floor flat. Strewn about is all manner of masculine-type clutter — investigative tools, dusty books, souvenirs from exotic lands, anatomical drawings, rotten apple cores, crushed walnut shells, neglected plants and preserved animals parts.

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Jude Law's dapper Dr. John H. Watson, preparing to leave both his bachelor and sleuthing days behind, packs up his belongings in the tidier portion of the apartment. Robert Downey Jr.'s wiry Sherlock Holmes, deeply perturbed by his friend's pending departure after a decade together as crime-fighting colleagues, answers a knock at the door.

Suddenly, a recently deceased body is dropped on a table in the middle of the room by two constables.

Watson: "Who is he?"

Holmes: "That's my new roommate."