Kennedy had evidently satisfied himself on one point.  If we were to get into that chamber we must do it ourselves, and we must do it quickly.

From the package which he carried he pulled out a stubby little cylinder, perhaps eighteen inches long, very heavy, with a short stump of a lever projecting from one side.  Between the stonework of a chimney and the barred door he laid it horizontally, jamming in some pieces of wood to wedge it tighter.

Then he began to pump on the handle vigorously.  The almost impregnable door seemed slowly to bulge.  Still there was no sign of life from within.  Had the bomb-maker left before we arrived?

“This is my scientific sledge-hammer,” panted Kennedy, as he worked the little lever backward and forward more quickly—­“a hydraulic ram.  There is no swinging of axes or wielding of crowbars necessary in breaking down an obstruction like this, nowadays.  Such things are obsolete.  This little jimmy, if you want to call it that, has a power of ten tons.  That ought to be enough.”

It seemed as if the door were slowly being crushed in before the irresistible ten-ton punch of the hydraulic ram.

Kennedy stopped.  Evidently he did not dare to crush the door in altogether.  Quickly he released the ram and placed it vertically.  Under the now-yawning door jamb he inserted a powerful claw of the ram and again he began to work the handle.

A moment later the powerful door buckled, and Kennedy deftly swung it outward so that it fell with a crash on the cellar floor.

As the noise reverberated, there came a sound of a muttered curse from the cavern.  Some one was there.

We pressed forward.

On the floor, in the weird glare of the little furnace, lay a man and a woman, the light playing over their ghastly, set features.

Kennedy knelt over the man, who was nearest the door.

“Call a doctor, quick,” he ordered, reaching over and feeling the pulse of the woman, who had half fallen out of her chair.  “They will, be all right soon.  They took what they thought was their usual adulterated cocaine—­see, here is the box in which it was.  Instead, I filled the box with the pure drug.  They’ll come around.  Besides, Carton needs both of them in his fight.”

“Don’t take any more,” muttered the woman, half conscious.  “There’s something wrong with it, Haddon.”

I looked more closely at the face in the half-darkness.

It was Haddon himself.

“I knew he’d come back when the craving for the drug became intense enough,” remarked Kennedy.

Carton looked at Kennedy in amazement.  Haddon was the last person in the world whom he had evidently expected to discover here.

“How—­what do you mean?”

“The episode of the telephone booth gave me the first hint.  That is the favourite stunt of the drug fiend—­a few minutes alone, and he thinks no one is the wiser about his habit.  Then, too, there was the story about his speed mania.  That is a frequent failing of the cocainist.  The drug, too, was killing his interest in Loraine Keith—­that is the last stage.