On went the Eurasian, up to her waist in the flood, with Max gaining upon her, now, at every stride.  There was a damp freshness in the air of the passage, and a sort of mist seemed to float above the water.  This mist had a familiar smell....

They were approaching the river, and there was a fog to-night!

Even as he realized the fact, the quarry vanished, and the ray of light from Max’s lamp impinged upon the opening in an iron sluice gate.  The Eurasian had passed it, but Max realized that he must lower his head if he would follow.  He ducked rapidly, almost touching the muddy water with his face.  A bank of yellow fog instantly enveloped him, and he pulled up short, for, instinctively, he knew that another step might precipitate him into the Thames.

He strove to peer about him, but the feeble ray of the lamp was incapable of penetrating the fog.  He groped with his fingers, right and left, and presently found slimy wooden steps.  He drew himself closely to these, and directed the light upon them.  They led upward.  He mounted cautiously, and was clear of the oily water, now, and upon a sort of gangway above which lowered a green and rotting wooden roof.

Obviously, the tide was rising; and, after seeking vainly to peer through the fog ahead, he turned and descended the steps again, finding himself now nearly up to his armpits in water.  He just managed to get in under the sluice gate without actually submerging his head, and to regain the brick tunnel.

He paused for a moment, hoping to be able to lower the gate, but the apparatus was out of his reach, and he had nothing to stand upon to aid him in manipulating it.

Three or four inches of water now flooded the cave of the golden dragon.  Max pulled the keys from his pocket, and unlocked the door at the foot of the steps.  He turned, resting the electric lamp upon one of the little ebony tables, and lifting Helen Cumberly, carried her half-way up the steps, depositing her there with her back to the wall.  He staggered down again; his remarkable physical resources were at an end; it must be another’s work to rescue Mrs. Leroux.  He stooped over Gianapolis, and turned his head.  The crooked eyes glared up at him deathly.

“May the good God forgive you,” he whispered.  “You tried to make your peace with Him.”

The sound of muffled blows began to be audible from the head of the steps.  Max staggered out of the cave of the golden dragon.  A slight freshness and dampness was visible in its atmosphere, and the gentle gurgling of water broke its heavy stillness.  There was a new quality come into it, and, strangely, an old quality gone out from it.  As he lifted the lamp from the table—­now standing in slowly moving water—­the place seemed no longer to be the cave of the golden dragon he had known....

He mounted the steps again, with difficulty, resting his shaking hands upon the walls.  Shattering blows were being delivered upon the door, above.