We proceeded up the bay on the Sylvania, but were able to discover nothing further that night. As we left the ship at the dock in the morning we ran across Wade, who was quietly directing a dozen or so of his men.

"Any trace yet of the Invincible?" asked Craig, stopping in an unostentatious corner.

The customs man shook his head gravely. "Not yet," he replied. "But I'm not discouraged. If we miss it here in the customs inspection it will be sure to turn up later. There's a shady jeweler on Fifth Avenue, Margot, who knows these Antwerp people pretty well. I have a man working there, a diamond cutter, and other agents in the trade. Oh, I'll hear about it soon enough, if it is here. Only I'd like to have done something spectacular, something that would count for me at Washington. Have you found out anything?"

Briefly Kennedy told him some of the scattered facts we had discovered, just enough to satisfy him without taking him into our confidence.

"I'm going to be busy in the laboratory, Walter," remarked Kennedy as our taxicab extricated itself from the ruck of the river-front streets. "I don't know that there is anything that you can do—except—well, yes. I wish you'd try to keep an eye on some of these people—that maid, Cecilie, especially."

We had learned that De Guerre was to stop at the Vanderveer and, later in the morning, I dropped into the hotel and glanced over the register. De Guerre was registered there and Cecilie had a little room, also, pending the disposal he would make of her. Miss Hoffman had rooms of her own, which she had evidently re-engaged, with a family in a residential street not far from the hotel.

The clerk told me that De Guerre was out, but that the maid had returned after having been out alone, for a short time, also. The lobby of the Vanderveer was fairly crowded with people by this time, and I found no difficulty in keeping in the background and still seeing pretty much everything that went on.

It was rather tame, however, and I was still debating whether I should not do something active, when I happened to glance up and catch sight of a familiar face. It was Dr. Preston making inquiries for someone of the room clerk. I dodged back of a pillar and waited, covering myself with an early morning war extra that repeated the news of the night before.

A few moments later, Preston, who had received an answer from whomever he was calling, edged his way toward one of the deserted little reception rooms near a side carriage entrance. Carefully, I trailed him.

It was some minutes before I could make up my mind to risk passing the door of the little parlor and being discovered, but I was growing impatient. As I glanced in I was astonished to see him talking earnestly to Cecilie. I did not dare stop, for fear one or the other might look up, but I could see that Preston was eagerly questioning her. Her face was averted from me and I could not read even her expression. The passageway was deserted, and if I paused I would inevitably attract attention. So I kept on, turning instinctively in the labyrinth and coming back to the lobby, where I found a position near the telephone booths which gave me a concealed view at least of the door of the parlor around an angle. I waited.