Sherlock Holmes is searching for a criminal.

The criminal assaulted several people, then spent the night at a hotel. He and Watson spent several hours searching the room top and bottom for DNA evidence left behind by the staff. Then, Watson had an idea. The idea was to look in the room’s sewage, for urine, waste, and dead skin cells. They ask the hotel for access, then Watson starts to inspect the pipes. After a while, Holmes tells Watson, “Dang it! The hotel must’ve already flushed it all out as per protocol. Watson turns around and shrugs. “No shit, Sherlock.”