He took the slip of paper from Captain Hardy and wrote some figures on it. "That," said he, "is my private telephone number. But do not bother me unless you get hold of something important."

In another moment the wireless party found itself in the rush and roar of lower Broadway.

CHAPTER V

THE MESSAGE IN CIPHER

The house to which Chief Flynn had directed the wireless patrol proved to be a private residence on a side street that ran between Central Park and the Hudson River. It was a tall house, standing two stories higher than any other structure in the block. Like most of its neighbors it had evidently seen better days. In places the brownstone front was cracked and great chips had flaked off. The broken stones in the long flight of steps that led up to the first floor were patched with colored cement that had faded so the patches stood out baldly. The brass handrail above the stone balustrade was battered and dirty. Altogether it was not a very attractive looking place.

The old lady who opened the door eyed them sharply.

"A gentleman named Flynn recommended me to your place," said Captain Hardy. "We shall need accommodations for quite a while."

"You must be the gentleman from Washington that he 'phoned me about. You are Captain Hardy?"

"I am."