Stuyvesant Verplanck had telephoned rather hurriedly to Craig earlier in the day, retaining his services, but telling only in the briefest way of the extent of the depredations, and hinting that more than jewelry might be at stake.

It was a pleasant ride, but we finished it in silence.  Verplanck was, as I recalled, a large masterful man, one of those who demanded and liked large things—­such as the estate of several hundred acres which we at last entered.

It was on a neck of land with the restless waters of the Sound on one side and the calmer waters of the bay on the other.  Westport Bay lay in a beautifully wooded, hilly country, and the house itself was on an elevation, with a huge sweep of terraced lawn before it down to the water’s edge.  All around, for miles, were other large estates, a veritable colony of wealth.

As we pulled up under the broad stone porte-cochere, Verplanck, who had been expecting us, led the way into his library, a great room, literally crowded with curios and objects of art which he had collected on his travels.  It was a superb mental workshop, overlooking the bay, with a stretch of several miles of sheltered water.

“You will recall,” began Verplanck, wasting no time over preliminaries, but plunging directly into the subject, “that the prominent robberies of late have been at seacoast resorts, especially on the shores of Long Island Sound, within, say, a hundred miles of New York.  There has been a great deal of talk about dark and muffled automobiles that have conveyed mysterious parties swiftly and silently across country.

“My theory,” he went on self-assertively, “is that the attack has been made always along water routes.  Under shadow of darkness, it is easy to slip into one of the sheltered coves or miniature fiords with which the north coast of the Island abounds, land a cut-throat crew primed with exact information of the treasure on some of these estates.  Once the booty is secured, the criminal could put out again into the Sound without leaving a clue.”

He seemed to be considering his theory.  “Perhaps the robberies last summer at Narragansett, Newport, and a dozen other New England places were perpetrated by the same cracksman.  I believe,” he concluded, lowering his voice, “that there plies to-day on the wide waters of the Sound a slim, swift motor boat which wears the air of a pleasure craft, yet is as black a pirate as ever flew the Jolly Roger.  She may at this moment be anchored off some exclusive yacht club, flying the respectable burgee of the club—­who knows?”

He paused as if his deductions settled the case so far.  He would have resumed in the same vein, if the door had not opened.  A lady in a cobwebby gown entered the room.  She was of middle age, but had retained her youth with a skill that her sisters of less leisure always envy.  Evidently she had not expected to find anyone, yet nothing seemed to disconcert her.