His young companions plied their leader with a thousand questions. They wanted to know the names of all the big buildings in sight. They had all heard of the Waldorf-Astoria Hotel and they gazed up Thirty-fourth Street at this well-known hostelry with much curiosity. They had heard of the Times Building and were eager to see it.

"We can't spend much time sightseeing just now," said Captain Hardy. "We must get into touch with the police and the secret service people and get our instructions. Then we will take a day or two, if possible, and see something of the town. It is most important for you to become well acquainted with it at once. But I guess we can take time to slip up to Times Square. It's only eight blocks up Broadway. Now I want you boys to see everything you can as we go along, and to try to remember all that you see. Wherever you go you must remember that you are in New York to detect German spies and presumably to run down German wireless outfits. We don't know where they are. We may be looking at one this very instant. So keep your eyes open. If you see anything that resembles a wireless outfit, or that might be used for sending messages, take careful note of it. And keep your ears open for suspicious conversations. Because you are boys, people will be less careful in their talk when you are present than they would be with older people about. The more youthful and unsophisticated you can make yourselves appear, the better it will be for your purpose."

Slowly the little party made its way up Broadway. By degrees the lads became accustomed to the roar of the traffic and the rush of pedestrians. At Times Square they paused for a look at the great newspaper building that gives the place its name, and at the great hotels rising on every side. Then they passed down a long flight of steps and found themselves in a low, vaulted, underground subway station.

"Makes you think of the dugouts on the firing-line in France," suggested the quick-witted Roy.

An instant later a train thundered up to the platform and the boys boarded it. A short ride and a short walk took them to Police Headquarters.

Captain Hardy sent his card to the Police Commissioner, with the request for a brief interview. A few moments later he had presented his credentials and introduced his companions, and four delighted boys found themselves blushingly shaking hands with New York's famous chief of police, Arthur Woods. Briefly Captain Hardy stated the purpose of his visit and related the story of the capture of the Elk City dynamiters.

"I recall the incident distinctly," said the Commissioner. "The newspapers were full of it. And I recall that when I read the story I wished I had as accomplished and clever a squad of boys to help me with some of my hard problems."

The four boys flushed with happiness. But they were too much embarrassed to make any reply.

"Captain Hardy," said the Commissioner, "what is your plan of action?"

"We have none as yet. We are to work under the direction of the secret service. But we have not seen Chief Flynn yet. The boys just arrived."