Some one had been at much pains and at more expense, to lay out and develop that secret trail.  For it is no easy or cheap task to build a sure path through such a swamp.  From a distance, forests of mangrove seemed to be massed on rising ground, and to group themselves about the sides and the crests of knolls.  As a matter of fact, the presence of a mangrove forest is a sign of the very lowest ground, ground covered for the most part by salt tidewater.  The lowest pine barren is higher than the loftiest mangrove wilderness.

Gavin Brice’s aspect of lassitude dropped from him like an outworn garment.  For hours—­except during his brief encounter with the beach comber—­he had been steadily on the move, and had covered a good bit of ground.  Yet, any one, seeing him as he traversed the miles from the Royal Palm Park at Miami, would have supposed from his gait that he was on some aimless ramble.  Now, alert, quick-stepping, eager, he made his swift way along the windings of the secret path.

Light as were his steps, they creaked lamentably at times on the boards of a bridge-span.  More than once, he heard slitherings, in the water and marsh to either side, as some serpent or other slimy swamp-dweller wriggled away, at his passing.  The collie trotted gravely along, just in front of him, pausing once in a while, as if to make certain the man was following.

The silence and gloom and sinister solemnity of the place had had a dampening effect on the dog’s gay spirits.  The backward glances at his self-chosen master were for reassuring himself, rather than for guidance.  Surroundings have quicker and stronger effect on collies than on almost any other kind of dog.  And these surroundings, very evidently, were not to the collie’s taste.  Several times, when the path’s width permitted, he dropped back to Gavin’s side, to receive a word of friendly encouragement or a pat on the head.

Outside of the grove’s shadows the sun was sinking.  Not with the glowing deliberation of sunsets in northern latitudes, but with almost indecent haste.  In the dense shade of the forest, twilight had fallen.  But the path still lay clear.  And Brice’s footsteps quickened, as in a race with darkness.

Then, at a twist of the path, the way suddenly grew lighter.  And at another turn, twilight brightened into clearness.  A hundred feet ahead was a thin interlacing of moonflower vines, compact enough, no doubt, to prevent a view of the path to any one standing in the stronger light beyond the grove, but making distinct to Brice a grassy clearing beyond.

Upon this clearing, the brief bright afterglow was shining, for the trim grass and shrubs of an upwardsloping lawn were clearly visible.  For some minutes the water and the swamp underfoot had given place to firmer ground, and the character of the trees themselves had changed.  Evidently, the trail had its ending at that screen of vineleaves draped between two giant gumbo-limbo trees at the lawn’s verge.