He and Jenkins had duplicate keys to the desks, letter-box, etc.
But if the note should not be in the letter-box, what would happen then?
It was not in the letter-box; it was not upon the person of the dead man.
Will you write down a message and leave it in his letter-box?
I know him, Lieutenant,—pardon—Monsieur Henri—a—letter-box—a go-between.
It fell into the letter-box with a thud, and she crept back like a guilty thing.
I watched him go up to the letter-box and then retrace his steps.
He had a key to his letter-box; he always came towards evening.
He crept down the stairs, opened the metal flap of the letter-box and listened.
That evening he found in his own letter-box a slip of paper.