Matthew's smile froze on his face as the girl opened her mouth, and he even recognised her voice! She must surely be someone he knew quite well. Was she one of the so-called "Muggles" unwilling to beg the Dark Lord for her magic and her job back in the Department of International Magical Co-operation? But... no, he was certain he was the youngest person in the Department before the regime change, and this girl was considerably younger than he was! Of course, he reminded himself, he looked even older than his true age, due to being so bloody careworn of late! But still -- it was quite easy to stress oneself into looking older, not so easy to stress oneself into looking younger! No, he knew this girl from somewhere else within the Ministry, surely...?
Caught up in his abstraction, he almost didn't hear the girl's question. "Sorry? Oh, no, mamselle!" He patted his pocket significantly -- at least, it would be significant if the girl were truly a witch, for he had shrunk his valise into his coat pocket. "I mean, my luggage is already at the docks!" he added quickly, just in case this was a Muggle girl, who was giving him such a peculiar sense of deja vu!
To try and explain away the patting of his pockets, just in case she was a Muggle, he drew out his purse -- which, thankfully, had a few Muggle notes in it. "How much for the room and supper?" he asked, with a sickly smile still frozen upon his countenance. What would he do, if it turned out this girl was a witch? He wasn't sure; certainly he didn't want to turn her in to his comrades-in-arms, for they were a bloodthirsty lot, and would undoubtedly kill half the population of Dover before they found the witch in question...!