house, but personally I am convinced that, knowing of the reception here
to-night, he would not think of using the conservatory."

"Most unlikely, I should say," the Professor murmured. "Craig is a very
shy man. He is at all times at your disposal, Mr. Quest, if you should
desire to question him."

Quest nodded absently.

"My assistant and I," he announced, "would be glad to make a further
examination of the conservatory, if you will kindly leave us alone."

They obeyed without demur. Quest took a seat and smoked calmly, with his
eyes fixed upon the roof. Lenora went back to her examination of the
overturned plants, the mould, and the whole ground within the immediate
environs of the assault. She abandoned the search at last, however, and
came back to Quest's side. He threw away his cigar and rose.

"Nothing there?" he asked laconically.

"Not a thing," Lenora admitted.

Quest led the way towards the door.

"Lenora," he decided, "we are up against something big. There's a new hand
at work somewhere."

"No theories yet, Mr. Quest?" she asked, smiling.

"Not the ghost of one," he admitted gloomily.