... He had sensed rather than heard it: someone or something was standing in the narrow gap between the garage and the fence behind him. Harry squinted at the black alleyway. If only it would move, then he'd know whether it was just a stray cat or – something else.
'Lumos,' Harry muttered, and a light appeared at the end of his wand, almost dazzling him. He held it high over his head, and the pebble-dashed walls of number two suddenly sparkled; the garage door gleamed, and between them, Harry saw, quite distinctly, the hulking outline of something very big, with wide, gleaming eyes.
As the title says, I don't understand "the pebble-dashed walls of number two". Is 'number two' the address number of someone's house or something?
-- From Harry Potter.