On that same evening, while Kennedy and Ella were having a light dinner together at the Piccadilly Grill before she went to the theatre, the elusive Ortmann called upon old Theodore Drost at the dark house at Castelnau, on the Surrey side of Hammersmith Bridge. He came in a taxi, and accompanying him was a grey-haired, tall, and rather lean man, who carried a heavy deal box with leather handle. Drost welcomed them, and all three ascended at once to that long attic, the secret workshop of the maker of bombs. The man who posed as a pious Dutch missionary switched on the light, disclosing upon the table a number of small globes of thin glass which, at first, looked like electric light bulbs. They, however, had no metal base, the glass being narrowed at the end into a small open tube. Thus the air had not been exhausted. "This is our friend, Doctor Meins," exclaimed Ortmann, introducing his companion, who, a few minutes later, unlocked the box and brought out a large brass microscope of the latest pattern, which he screwed together and set up at the further end of the table. Meanwhile from another table at the end of the long apartment old Drost, with a smile of satisfaction upon his face, carried over very carefully a wooden stand in which stood a number of small sealed glass tubes, most of which contained what looked like colourless gelatine. "We want to be quite certain that the cultures are sufficiently virulent," remarked Ortmann. "That is why I have brought Professor Meins, who, as you know, is one of our most prominent bacteriologists, though he is, of course, naturalised as a good Englishman, and is in general practice in Hampstead under an English name." The German professor, smiling, took up one of the hermetically sealed tubes, broke it, and from it quickly prepared a glass microscope-slide, not, however, before all three had put on rubber gloves and assumed what looked very much like gas-helmets, giving the three conspirators a most weird appearance. Then, while the Professor was engaged in focussing his microscope, Drost, his voice suddenly muffled behind the goggle-eyed mask, exhibited to Ortmann one of the glass bombs already prepared for use. It was about the size of a fifty-candle-power electric bulb, and its tube having been closed by melting the glass, it appeared filled with a pale-yellow vapour. "That dropped anywhere in a town would infect an enormous area," Drost explained. "The glass is so thin that it would pulverise by the small and almost noiseless force with which it would explode." "It could be dropped by hand--eh?" asked Ortmann. "And nobody would be the wiser." "No, if dropped by hand it would, no doubt, infect the person who dropped it. The best way will be to drop it from a car." "At night?" "No. In daylight--in a crowded street. It would then be more efficacious--death resulting within five days to everyone infected."