I followed every word intently. “Nothing at all about the loss of the Alaska or the Dreadnought Number 8?” I asked significantly.

“No,” answered Dorothy.

“When was the letter mailed?” I asked.

“Two days after the British ship went down,” she answered. “But—” She stopped as Tom came in. I continued the conversation no farther.

As I left, Tom called after me. “I’ve been fooling with some phosphorescent paint,” he said, “and I’ve run down a few interesting results. Don’t you want to come up to the laboratory to-morrow morning about three o’clock? We’re going to run some tests between twelve midnight, and five in the morning, so as to have the least current and vibration that the city can give.”

“I’ll be glad to come,” I answered instantly. No chance to be near Dorothy was ever to be refused.

The last revellers were just passing from the great white way, as I rode up town in a late surface car, which held, beside myself, only a few dull and sleepy workers. I was ahead of time and, as I came up near Riverside Drive, I jumped off the car and walked down towards the Drive and up by the river. Below me, in the full moonlight, lay an American fleet. The white sides and lofty turrets of the ships stood sharply outlined against the other bank. They seemed to personify the might of the nation resting there in huge impassive stolidity, fearful of nothing, ready for all. Yet as I remembered Joslinn’s words, “vanished like a breaking soap bubble,” spoken of the Alaska, I shuddered at the helplessness of those floating forts, massive as they were. I looked at my watch in the moonlight. Quarter of three. I turned and made my way to the gray stone building on the height, which held the research laboratory.

I found Tom and Dorothy bending over a series of instruments under a big incandescent light. I watched them for a moment silently, then, as they rose from their task, I greeted them. Never had Dorothy looked more charming than in this setting of bare walls and severe tables, hooded instruments and wires, glass cases and shelves. Most girls whom I had seen at three o’clock in the morning, as they left a ballroom, were sorry spectacles, worn and dishevelled. Dorothy, in her trim working clothes, was as fresh as a summer’s morn. Her first greeting over, she turned to her work again, adjusting a micrometer levelling screw.

“What are you doing?” I asked idly.