“Only an elderly housekeeper, of whom I don’t hear anything very good,” replied Nick.  “Venner is here but part of the time, I am told.  In fact, I don’t quite fathom his habits.”

“Why so?”

“I can’t learn what takes him from home so much of the time.  He does not leave the city, nor patronize any hotel that I can discover, yet he frequently is away from this house overnight.”

“Perhaps he secretly keeps another house, and is leading a double life.”

“Possibly,” admitted Nick.  “He is on friendly terms with numerous women, I learn, and other quarters may be essential to designs of some kind.  Quietly, now, and we’ll slip across the back lawn.”

Like shadows, as dark as the night itself, they silently reached a point from which they could view the north side of the house.  Here they discovered that one of the lower rooms was lighted, with the curtain at the single window nearly drawn.

“Somebody is up,” murmured Chick.

“We’ll learn who, if possible.”

“Going to have a look?”

“Yes.  Come, if you like, but don’t get into the glare from the curtain.  Kilgore has a very wicked air gun, and if he and his gang are about here, we might invite a bullet.”

“I’ll have a care.”

Stealing closer over the damp greensward, they approached the house and peered beneath the curtain mentioned.  There was but one occupant of the room, which was a small library.

In an easy-chair near the table, with a newspaper fallen across his knees, sat Rufus Venner, apparently sound asleep.

This was only a part of the game, however, for Venner was wide awake.  By means of their secret wire, he had been informed of Cervera’s arrival at the diamond plant, and of Kilgore’s designs upon Nick, and Venner at that moment suspected that he might be under the eye of the detective.

For nearly half an hour Nick waited for some sign of this artifice, but Venner in no way betrayed it.

Presently a clock on the mantel struck the half after one, and the sound appeared to awake him.  He yawned, glanced at the clock, then took the lamp from the table and went up to bed.  But never so much as a glance toward the window.

Nick led Chick away, and they returned across the lawn to a point beyond the stable.

“It rather looks as if Cervera had been here, doesn’t it?” inquired Chick, with a grin.

“Yes,” admitted Nick.  “Two facts are very significant of it.  First, that Venner is at home on this particular night; and, second, that he should be asleep in his chair after midnight.  It has a fishy look.”

“That’s my idea, Nick, exactly.”

“Yet the way to prove it doesn’t appear quite easy.”

“Not just yet.  But who occupies that house over yonder, where the roof shows above the trees?”

And Chick pointed to the distant dwelling, little dreaming that the diamond plant and the gang they sought were established under its many-gabled roof.