“Where is Mizzentop?”

“Why, Mizzentop was one of the fashionable resorts of this country, my boy, during the ’70’s and ’80’s. It’s up on the mountain above Pawling, New York, and nine or ten miles across the hills from Heartfield’s. The house Fanely blew up must have been purchased so that the Professor could have a hangout conveniently close by and yet not near enough to arouse suspicion if discovered. Mizzentop is really the name of the old hotel up there, from which the little settlement takes its name.”

They stepped behind a high bank of shrubbery, beyond which they could see the dim blur of the lodge in the darkness.

“That,” said Bill, “seems to me a queer place to locate a laboratory—right near a summer hotel, I mean.”

“Oh, the hotel isn’t running now—hasn’t been for thirty years or more. I was up there a couple of summers ago. It’s a huge frame building, three or four stories high, with wide verandas completely encircling it. It seemed to be in pretty good condition, then. Somebody was evidently taking care of the property, lawns kept up and so forth, but the place was untenanted.”

“I wonder—”

“What? Have you got an idea? Let’s have it then we’ll go after Osceola.”

“Well, I was just figuring,” Bill’s voice sounded thoughtful, “suppose Professor Fanely had bought that hotel and is using it for his laboratory, or whatever he calls it.”

The detective slapped his thigh sharply. “That is a new slant on it, Bill! Sounds like a good one to me. Just as soon as we get Osceola I’ll check up on it by telephone. In fact, I’ve a lot of phoning to do. Captain Simmonds and the State Police will have to be brought in now, Washington or no Washington!”

“But do you think Fanely will fly up there as he plans to do—when we’re found missing?”