“What do you make of that, Lomax?” he asked.

“Of course,” murmured the Professor, “Hetty’s mind may be influenced by a dominant anxiety in yours.—I should not like to say, Forsdyke!” His tone was emphatic. “Personally, I have never heard of a spectral spy—but—well, you are, on your showing worth spying on. And there are more things in heaven and earth, Horatio—you know! If it is possible—then there are things more improbable than that this means of acquiring information should be used. Your schedule would, I take it, be priceless?”

“The fate of the world may be involved in it,” replied Forsdyke. “But I can’t believe——”

“I am certain!” exclaimed Hetty. “I feel there’s something uncanny around us now!” She shuddered. “Oh, do take care, Poppa!”

“But what can he do?” asked Jimmy, who had been listening anxiously to the Professor’s explanation. “What do you suggest, Sergeantson? You’re the authentic spycatcher. How can you defeat the ghost of one?”

“I pass!” replied Sergeantson, laconically. “Professor, the word’s to you!”

Forsdyke looked genuinely worried.

“Of course, I don’t believe it, Lomax,” he said. “But supposing—supposing there was something like you suggest—what could I do?”

The Professor’s eyes twinkled.