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?"