Hammersmith, had struck two o'clockwhen across the long suspension-bridge a tall man in a black waterproofcoat and black plush hat walked with a swing, smoking a cigarette, andpassed hurriedly out into the straight broad thoroughfare of Castelnau.
For some distance he proceeded, then suddenly he slackened pace, glancedat the luminous watch upon his wrist, and, a few moments later, haltedagainst some railings, and, looking across the road, waited patientlyopposite the house occupied by the pious Dutch pastor, the ReverendTheodore Drost.
The house was in darkness, and there was not a sound in the street savethe barking of a dog at the rear of a house in the vicinity.
In patience, Flight-Commander Kennedy, for it was he, waited watchfully.He remained for a full quarter of an hour, ever and anon glancing athis watch, until, of a sudden, the front door opposite was openednoiselessly, and he saw the gleam of a flash-lamp.
In a moment he had crossed the road and, ascending the steps, met hiswell-beloved. As he met her, he thought how strange it all seemed, whata romance it was. Here was this charming girl, whom the world only knewas a celebrated revue artiste, helping him to frustrate the criminalplans of her German father.
Ella, standing at the door, whispered:
"Hush!"
And without a word Seymour Kennedy, treading tiptoe, slipped within.
The house was familiar to him. He grasped the soft white hand of hiswell-beloved and, raising it to his lips, kissed it in homage. She waswearing a dainty purple and yellow kimono, her little feet thrust intored morocco Turkish slippers, which were noiseless, and, as she ascendedthe thickly-carpeted stairs, he followed her without uttering a word.
Up they went, to the top floor. The door which faced them at the headof the stairs she unlocked with a key, and after they were both insideshe closed the door and then switched on the light.
The big chemical laboratory, which her father had established in secretin that long attic, presented the same scene as it had when he hadvisited it before at the invitation of his well-beloved. With suchconstant demands upon his inventive powers, it was necessary that thePrussian ex-professor should have the place fitted up with all thelatest scientific appliances.
"Well, Seymour!" the girl exclaimed at last. "Here you are! What doyou think of these?" And, crossing to a side table, she indicated twowell-worn attache-cases in brown leather, each about sixteen inches byeight, and three inches deep.
One of them she opened, revealing a curious mechanism within, part ofwhich was the movement of a cheap American clock. Her tall,good-looking companion, who was a skilled mechanic, examined both theseinnocent-looking little cases with keen interest, and then exclaimed:
"Ah! I quite understand now! These are no doubt to be used inconjunction with explosives. They run for half an hour only, and thenelectrical contact is made into the explosive compound."
"Exactly. See there, that row of tins of lubricating-oil. They arealready filled with the high-explosive and in readiness."
Kennedy bent and then saw, ranged below a bench on the opposite side ofthe laboratory, six tins of a certain well-known thick lubricating-oilused by motorists.
"There is sufficient there, dear, to blow up the whole of Barnes," shedeclared. "Evidently this latest outrage is intended to be a seriousone."
"Ah!" sighed Kennedy. "It is a thousand pities, Ella, that your fatheris doing all this dastardly secret work for the enemy. Happily you,though his daughter, are taking measures to thwart his plans."
"I am doing only what is my duty, dear," replied the girl in the kimono;"and with your aid I hope to upset this latest plot of Ortmann and hisfriends."
"Have you seen Ortmann lately?" her lover asked.
"No. He has been away somewhere in Holland--conferring with the GermanSecret Service, without a doubt. I heard father say yesterday, however,that he had returned to Park Lane."
"Returned, in order to distribute more German money, I suppose?"
"Probably. He must have spent many hundreds of thousands of pounds inthe German cause both before the war and after it," replied the girl.
The pair stood in the laboratory for some time examining some of theapparatus which old Drost, now sleeping below, had during that day beenusing for the manufacture of the explosive contained in thoseinnocent-looking oil-cans.
Kennedy realised, by the delicacy of the apparatus, how well versed thegrey-haired old Prussian was in explosives, and on again examining theattache-cases with their mechanical contents, saw the cleverness withwhich the plot, whatever its object, had been conceived.
What was intended? There was no doubt a conspiracy afoot to destroysome public building, or perhaps an important bridge or railwayjunction.
This he pointed out to Ella, who, in reply, said:
"Yes. I shall remain here and watch. I shall close up my flat, andsend my maid on a holiday, so as to have excuse to remain here at home."
"Right-ho! darling. You can always get at me on the telephone. Youremain here and watch at this end, while I will keep an eye on Ortmann--at least, as far as my flying duties will allow me."
Thus it was arranged, and the pair, treading noiselessly, closed thedoor and, relocking it, crept softly down the stairs. In the dark hallSeymour took his well-beloved in his strong arms and there held her,kissing her passionately upon the brow. Then he whispered:
"Good-night, my darling. Be careful that you are not detectedwatching."
A moment later he had slipped out of the door and was gone.
Hardly had the door closed when Ella was startled by a movement on thelanding at the head of the stairs--a sound like a footstep. There was aloose board there, and it had creaked! Some one was moving.
"Who's there?" she asked in apprehension.
There was no reply.
"Some one is up there," she cried. "Who is it?"
Yet again there was no response.
In the house there was the old servant and her father. Much puzzled atthe noise, which she had heard quite distinctly, she crept back up thedark stairs and, finding no one, softly entered her father's room, todiscover him asleep and breathing heavily. Then she ascended to theservant's room, but old Mrs Pennington was asleep.
When she regained her own cosy room, which was, as always, in readinessfor her, even though she now usually lived in the flat in StamfordhamMansions, over in Kensington, she stood before the long mirror andrealised how pale she was.
That movement in the darkness had unnerved her. Some person had mostcertainly trodden upon that loose board, which she and her lover hadbeen so careful to avoid.
"I wonder!" she whispered to herself. "Can there have been somebodywatching us?"
If that were so, then her father and the chief of spies, the manOrtmann, would be on their guard. So, in order to satisfy herself, shetook her electric torch and made a complete examination of the house,until she came to the small back sitting-room on the ground floor.There she found the blind drawn up and the window open.
The discovery startled her. The person, whoever it could have been,must have slipped past her in the darkness and, descending the stairs,escaped by the way that entrance had been gained.
Was it a burglar? Was it some one desirous of knowing the secrets ofthat upstairs laboratory? Or was it some person set to watch hermovements?
She switched on the electric light, which revealed that the room was asmall one, with well-filled bookshelves and a roll-top writing-table setagainst the open window.
Upon the carpet something glistened, and, stooping, she picked it up.It was a woman's curb chain-bracelet, the thin safety-chain of which wasbroken.
Could the intruder have been a woman? Had the bracelet fallen from herwrist in her hurried flight? Or had it fallen from the pocket of aburglar who had secured it with some booty from a house in the vicinity?
Ella looked out into the small garden, but the intruder had vanished.Therefore she closed the window, to find that the catch had been brokenby the mysterious visit
or, and then returned again to her room, whereshe once more examined the bracelet beneath the light.
"It may give us some clue," she remarked to herself. "Yet it is of veryordinary pattern, and bears no mark of identification."
Next day, without telling her father of her midnight discovery, she metSeymour Kennedy by appointment at the theatre, showed him what she hadfound, and related the whole story.
"Strange!" he exclaimed. "Extraordinary! It must have been a burglar!"
"Or a woman?"
"But why should a woman break into your house?"
"In order to watch me. Perhaps Ortmann or my father may havesuspicions," replied the actress, arranging her hair before the bigmirror.
"I hope not, Ella. They are both the most daring and the mostunscrupulous men in London."
"And it is for us to outwit them in secret, dear," she replied,