The emissaries had thrown the rope over a beam which was far above Locke, and it seemed an impossibility for him to reach it.  For one less resourceful or with a physique less perfectly developed, even to try would have been useless.  But there was one chance in a thousand, and he grasped it eagerly.

Alternately contracting and relaxing his muscles, Locke succeeded in swinging himself in an ever-widening arc.  Nearer he swung—­back—­and again nearer.  Could he make it?  Back again and a terrific effort.  He was gaining.

There came to him the sound of running feet.  In his fear and agony he could have shrieked, but from his parched throat there issued no sound.  Friend or foe, for him it meant the same fate—­one touch on that knob and a torturing death by fire.

With bursting muscles he redoubled his efforts.  In a long sweep his body swayed out and up.  Would he be in time?  Those pattering feet, they were coming nearer and nearer.  There were now but a few yards between them and that knob.

A mighty swing, a monstrous heave, his fingers crooked talon-like, and he touched the rafter, clutched—­and missed.

Downward and backward, his mind now reeling in black despair.  He had tried and failed.  This was the end.  The sound of footsteps had ceased.  Well he knew that some one was at the door.  He tried to pray and then—­he crashed against the rafter.  Mechanically he grasped at it and clung.

The door flew open, and there stood Eva.  All the horrors of imminent death, even the pain of sorely tried muscles, were momentarily forgotten in his relief at seeing her safe and having saved himself.  But not yet was he free.  The emissaries had been thorough in their work, but it was not many moments before the last knot was loose and he dropped to the floor.

Locke peered stealthily about.  To all appearances everything was clear.  He placed his arm about Eva and they started to steal out.  Well they knew that, with such enemies, not for a moment would they dare relax their caution.  For them every angle and nook was a temporary haven.  Slowly they drew away from the dread spot, and soon came to a more populous locality where the lights of honest shops and peaceful homes gave them a sense of greater security and brought a feeling of unreality to the horrors through which they had passed.

A taxi-driver hailed them, and in a short time they were rolling along the Cliff Drive and had arrived at Brent Rock.

It was the following day that the old butler handed Locke a letter addressed to International Patents, Incorporated, from the Diving and Salvage Company.  Locke was about to read it, when Eva entered and they read it together.

“We are reliably informed,” read the letter, “that the Under Seas Corporation is trying to obtain possession of the self-liberating diving-suit which you control in our interest.  This must be prevented.”

Locke was immediately interested.  At once it occurred to him that here was a patent which the company had suppressed which might prove of incalculable value.