Tom, Pepper, and Trusty by L.T. Meade

It was apparently the merest chance in the world that brought the old gentleman, who lived in -- Russell Square, to his hall-door the next morning, to answer, in his own person, a very small and insignificant-sounding ring. When he opened the door he saw standing outside a very tiny boy, and by the boy's side a most disreputable-looking dog.

"Well," said the old gentleman, for he hated beggars, "what do you want? Some mischief, I warrant."