The three individuals beaten down by Shard were merely ordinary members of the Black Hand Gang and didn't know much. Under the threat of force, they quickly divulged the information they held — the Black Hand Gang refused to give up hope that the three missing cards might still be in this house, so they sent them to search again.
Shard wasn't interested in them, so he instructed them to stay put. He searched the house himself and finally found a "Harry Gilot" business card in the corner of the desk's cardholder. He memorized the information on the card, put it back, and then left with Mia.
Mr. Harry Gilot was a local businessman dealing in tobacco, his shop located in the dock area, evidently targeting sailors.
