He had waited there for ten minutes or so, watching the dark, silent house, when, slowly and noiselessly, the front door opened, and next moment Kennedy and Ella were face to face. The latter wore a pretty pale-blue dressing-gown, for she had just risen from bed, she having spent the last two days at her father’s house.
With a warning finger upon her lips, and with a small flash-lamp in her hand, she led her lover up three flights of stairs to the door of that locked room, which she silently opened with her duplicate key.
“Father and the man Hans Rozelaar have been at work here nearly all day,” she whispered, when at last they halted before the long deal table upon which stood Drost’s chemical apparatus.
Kennedy’s shrewd eyes were quick to notice what was in progress in secret.
With some curiosity he took up a tube of tin about a foot long and four inches in diameter. On examining it he saw that through the centre was a second tin tube of about an inch in diameter. Holding it as a telescope towards the light he could see through the inner tubes and noticed that near one end of it a small steel catch was protruding. Further and minute examination revealed that to the catch could be attached a time-fuse already concealed between the inner and outer tubes.
“This is evidently some ingenious form of hand grenade,” whispered Kennedy. “It’s all ready for filling. But why, I wonder, should a tube run through the middle in this way?”
He was pondering with it in his hand, when his gaze suddenly fell upon something else which was lying close to the spot where he found the tin tube.
It was a thin ash walking-stick. On Kennedy taking it up it presented a peculiar feature, for as he grasped it there sounded a sharp metallic click. Then, to his surprise, he discovered that he had inadvertently released a spring in the handle, this in turn releasing four small steel points half-way down the stick.
“Curious!” he whispered to his well-beloved, for Drost was sleeping below entirely unconscious of the intruders in his secret laboratory. “What connection can the stick have with the grenade—if not for the purpose of throwing?”
He therefore placed the inner tube over the little knob of the stick, and found that it just fitted, so that with plenty of play it slid down as far as the projecting points which, after striking the little steel catch which would be connected with the fuse, allowed it to pass over freely and leave the stick.