s one of the most daring of
motor-boat enthusiasts.

"It may have been the work of an incendiary," he continued thoughtfully,
"or it may not. I don't know. But there has been an epidemic of fires
among the large houses out on Long Island lately."

I nodded to Kennedy, for I had myself compiled a list for the _Star_,
which showed that considerably over a million dollars' worth of show
places had been destroyed.

"At any rate," added the Countess, "we are burned out, and are staying
in town now--at my father's house. I wish you would come around there.
Perhaps father can help you. He knows all about the country out that
way, for his own place isn't a quarter of a mile away."

"I shall be glad to drop around, if I can be of any assistance," agreed
Kennedy as the young couple left us.

The Rovignos had scarcely gone when a woman appeared at the laboratory
door. She was well dressed, pretty, but looked pale and haggard.

"My name is Mrs. Bettina Petzka," she began, singling out Kennedy. "You
do not know me, but my husband, Nikola, was one of the first students
you taught, Professor."

"Yes, yes, I recall him very well," replied Craig. "He was a brilliant
student, too--very promising. What can I do for you?"

"Why, Professor Kennedy," she cried, no longer able to control her
feelings, "he has suddenly disappeared."

"What line of work had he taken up?" asked Craig, interested.

"He was a wireless operator--had been employed on a liner that runs to
the Adriatic from New York. But he was out of work. Someone has told me
that he thought he saw Nikola in Hoboken around the docks where a number
of the liners that go to blockaded ports are laid up waiting the end of
the war."

She paused.

"I see," remarked Kennedy, pursing up his lips thoughtfully. "Your
husband was not a reservist of any of the countries at war, was he?"

"No--he was first of all a scientist. I don't think he had any interest
in the war--at least he never talked much about it."

"I know," persisted Craig, "but had he taken out his naturalization
papers here?"

"He had applied for them."

"When did he disappear?"

"I haven't seen him for two nights," she sobbed.

It flashed over me that it was now two nights since the fire that had
burned Rovigno's house, although there was no reason for connecting the
events, at least yet.

The young woman was plainly wild with anxiety. "Oh, can't you help me
find Nikola?" she pleaded.

"I'll try my bes