The boy was not there, but a moment later Jack detected him among the waiting crowd at the post-office opposite.

With a view of following up his inquiries, he crossed the road as the boy entered the vestibule of the post-office.

He arrived in time to see him unlock one of a row of numbered letter-boxes rented by subscribers, which occupied a partition by the window, and take out a small package and a letter.
But in that brief glance Mr.Hamlin detected the printed address of the "Excelsior Magazine" on the wrapper.

It was enough.

Luck was certainly with him.
He had time to get rid of the wicked sparkle that had lit his dark eyes, and to lounge carelessly towards the boy as the latter broke open the package, and then hurriedly concealed it in his jacket-pocket, and started for the door.