Upon arriving in Clark, Billy went to the hotel, as this was his gang's meeting place. Before he got into town, he disguised himself like a gold miner, as there were lots of gold mines around there. Once inside the hotel he said to the clerk that he was staying with friends in room 24 and that he would like the extra key.
The clerk gave him the key, saying that he wanted it back, and that his bill was $47 because his friends were there for a while already. Billy paid the bill, and soon disappeared up the steps, and as he found room 24, he gave a knock, paused, then gave two more, knowing that he really didn't need the extra key, but it was extra security against snoops.