"That depends on what you need someone to matter for, doesn't it," he returns, unruffled as Sirius jerks in the unsubtle astonishment almost unavoidable when a lion and serpent cross paths without a war or House Cup looming. "It'd be best if you stayed out of the Alley entirely, really, so I could truthfully tell them you couldn't have seen me come in, but there are ways around that sort of thing if you've other business," he finishes tactfully, meaning if you'd rather not trust me for it. "Getting lost in the shelves where they can keep an eye on your inattentiveness should do it."