“Now, tell me all you can of this affair, and talk as quickly as you can,” directed the detective.

Tom told his brief but potent narrative without pausing for breath.

“I have telegraphed or telephoned men from our agency, so that many points are covered for some distance north along the coast,” murmured Mr. Musgrave. “We are also having the islands watched as far around as Block Island. But, since the launch was found running wild and the cabin sloop was not sighted, I am inclined to believe that the trail runs somewhere on the mainland. If you’ll take your friend, Joe Dawson, along with you, I’ll send also one of the Wood’s Hole constables, a man named Jennison. If you run into any of that crew, Jennison has power to make arrests, and he’s the sort of man who wouldn’t back down before a cannon. I have an automobile ready, and Jennison knows what’s expected of him. You’re to search up along the coast, to see if you can find any trace of that cabin sloop.”

“Do you think Jed Prentiss will be sufficient guard to leave with the boat?” questioned Halstead. “The Alvarez crowd would like nothing better than to disable this fine craft if they got a chance to sneak aboard.”

“I’ll send down one of the hotel employés to keep Prentiss company, then. Now come along, Halstead. Jennison and the automobile are waiting.”

Two minutes later Tom and Joe found themselves speeding along a road that led up along the coast.

“There’s no use stopping the first mile or so,” explained Constable Jennison, a slight but wiry-looking man of rustic type. “We’ve been over the near ground already. But we’ll go forty miles or more before we give up the search for the home berth of that sloop.”

Just below Falmouth the auto-car turned from the road to run down to a cove where several sailing craft and two launches were at anchor. The owner was found. He did not own or know of any such sloop as Halstead described.

On again they went. There was a chauffeur on the front seat The constable and the boys were in the tonneau. Two more boat-letting resorts were visited, but without success. The constable, however, far from being depressed, became jovial.

“Are you armed, Halstead?” he inquired, a twinkle in his eyes.