And they are trying to get some line on who he is ....

The moon is coming up.

That won't help them, to any great extent." He turned back into the room, partly shutting the door behind him.

But he did not finish the process of closing it.
For--sweet, faint, yet distinct to them all--the soaring notes of a mocking-bird's song swelled out on the quiet of the night.
"Rodney Hade!" gasped Standish.

"It's his first signal.