The newcomer was slender, graceful, with the form of an athletic boy rather than of a mature man.  He was pallid and black eyed.  His face had a classic beauty which, on second glance, was marred by an almost snakelike aspect of the small black eyes and a sinister smile which seemed to hover eternally around the thin lips.  His whole bearing suggested something serpentine in its grace and a smoothly half-jesting deadliness.

So much the first glimpse told Brice as he stood thereon the stairs and surveyed the doorway.  The second look showed him the man was clad in a strikingly ornate yachting costume.  Gavin’s mind, ever taught to dissect trifles, noted that in spite of his yachtsman-garb the stranger’s face was untanned, and that his long slender hands with their supersensitive fingers were as white and well-cared-for as a woman’s.

Yachting, in Florida waters at any time of year, means either a thick coat of tan or an exaggerated sunburn.  This yachtsman had neither.

Scarce taller than a lad of fifteen, yet his slender figure was sinuous in its every line, and its grace betokened much wiry strength.  His face was that of a man in the early thirties,—­all but his eyes.  They looked as old as the Sphinx’s.

He stood for an instant peering into the room, trying to focus his night-accustomed eyes to the light.  Evidently the first objects he saw clearly were Milo and Claire standing with their backs to him as they stared upward in blank dismay at the guest they had thought safely disposed of for the night.

“Well?” queried the man at the door, and at sound of his silken. bantering voice. brother and sister spun about in surprise. to face him.

“Well?” he repeated, and now there was a touch of cold rebuke in the silken tones.  “Is this the way you keep a lookout for the signals?  I might very well have walked in on a convention of half of Dade County, for all the guard that was kept.  I compliment—­”

And now he broke off short in his sneering reproof, as his eyes chanced upon Gavin half way down the stairs.

For a second or more no one spoke or moved.  Claire and her brother had an absurdly shamefaced appearance of two bad children caught in mischief by a stern and much feared teacher.  Into the black depths of the stranger’s eyes flickered a sudden glint like that of a striking rattlesnake’s.  But at once his face was a slightly-smiling mask once more.  And Gavin was left doubting whether or not he had really seen that momentary gleam of murder behind the smiling eyes.  It was Claire who first recovered herself.

“Good evening.  Rodney,” she said. with a graciousness which all-but hid her evident nerve strain.  “You stole in on us so suddenly you startled me.  Mr. Brice, this is Mr. Rodney Hade.”

As Gavin bowed civilly and as Hade returned the salutation with his eternal smile.  Milo Standish came sufficiently out of his own shock of astonishment to follow his sister’s mode of greeting the new visitor.  With the same forced joviality he had used in coercing Brice to go to bed, he sauntered over to the smiling Hade, exclaiming: