The bell that rang to announce Abby's presence in the shop was unnecessary. Liam did indeed feel the presence of another immortal and when he stepped out from his back room, he smiled pleasantly enough. He was just glad Alastair wasn't there because if this got ugly, he didn't want his human involved.
She looked nice enough though.
"Hello," Liam said, glancing around to make sure the shop was empty of others as well, before saying, "people like you don't usually come in here."