Short of an airship, he could conceive no device whereby the missing six could have made their silent departure. He was shaken out of his stupor by Haredale.
"Pull yourself together, Mr. Alden," cried the latter. "Can't we do something? Here's half Scotland Yard in the place and nobody with an intelligent proposal to offer."
Mr. Alden shook himself, like a heavy sleeper awakened.
"Where's Miss Oppner?" he jerked.
Haredale started.
"I don't know," was his reply; "but I can go and see."
He forced his way past the knot of people at the door, ignoring Inspector Sheffield, who sought to detain him. Rapidly he ran through the rooms composing the suite. In one he met Zoe's maid, wringing her hands with extravagant emotion.
"Where is your mistress?"
"She has gone out, m'sieur. I cannot tell where. I do not know."
Haredale's heart gave a leap—and seemed to pause.