After visiting the summerhouse, Stanley and John were escorted into the surrounding hills from whose summits they could see clearly in all directions along the back of the “porpoise” out to sea, and across the bay towards the distant spires and factory stacks and the Watch Tower Hill of Centerport. Paths in a veritable labyrinth of foot-ways radiated in and about the hills, but Mr. Nevens’ easy-going guidance gave hints that he was avoiding several by-ways purposely. What might some of these paths lead to? Stan meant to find out later!

The Water Witch was almost hidden on the far side of the cove against the background of trees and it certainly looked good. The entrance channel to the cove was seen as a narrow slit, cutting at an angle through the hills to the sea, and Stan made mental notes of its position. While they stood on a rock atop the highest hump of land, Mr. Nevens’ eyes rested rather long upon the moving form of a yacht which was coming in from the sea. White and shiny with brass work, the pleasure craft moved in the general direction of the island, though still some miles away.

“You will come back to see me again, boys, won’t you?” asked Mr. Nevens as they went down the hill. “I’ll show you my landing-stage and boat-house so that you’ll know where to tie up next time. You must come and spend a few days with me soon.”

This tactful remark could mean only one thing, since Mr. Nevens knew that the boys had intended staying in the cove longer than that one day. There was no alternative but to say what Stan now said.

“Certainly, Mr. Nevens. We’re pushing off now for a cruise further along but we’ll stop back next week if we get a chance!” Was the coming yacht bringing special visitors for the queer Mr. Nevens, and on criminal errands, since he wished the boys to move on now?

They were now shown the boat-house, a carefully laid out spot with a wide, high entrance into which a boat could come to land passengers and a mooring-stage beyond for bigger craft. The sudden disappearance of the speedboat of the previous night was now explained and Stan and John looked at each other with knowing grins.

At the mooring-stage was a fast-appearing speedboat of gray color and fast design, low in the water, with no visible exhaust, and fitted for luxurious water travel at high speed. The long, hooded middle section betrayed the huge, powerful engine hidden there. And in the “driver’s” seat sat a clean-shaven, uniformed attendant at ease, smoking a pipe quietly. Stan got an impression that the man was there in case of urgent need. Perhaps such a man was kept handy day and night!

Bidding their host at last good-day, the boys now went past the cabin, and up into the path round the cove. They wound along through the bushes a few minutes later, quietly, some sixth sense warning them not to comment on what they had seen and this caution was rewarded for, silently as they went in their bare feet, they came face to face with Dago! Startled, for he had apparently heard nothing of their approach, the swarthy fellow purpled and went pop-eyed. There was no doubt in the mind of the G-man’s son that Dago, insane or not, had a healthy fear of him and his friend and desired no part of their company.

“Hello, Mr. Dago,” John greeted him. “Nice here on the island, isn’t it?”

“Yes, it’s-a fine! I think I get along. Don’t see too much!”