Roger, finally, decided that there was one sure and final word to be said by chemistry. If, as Ellison insisted, other chemicals than actual burning gas caused the inside of the paraffin moulds to discolor, the special tests for the chemicals he might name would say if Ellison was truthful or not—a sort of chemical “Lie Detector,” Roger confided to Potts as they prepared for the experiments.
To their amazement, Ellison was proved honest. The tests gave a reaction for the very chemical he named.
The Tibetans, of course, had to be released. They were warned, and departed.
With the experiments done, the materials removed and no gain, Tip brought up the curious situation revealed by developing the office camera film and others.
“Here is the picture that Roger said he had it take,” Tip displayed, to the group assembled in the screening room, one “frame” of the non-flam film.
There were the Three, the Tibetan group, confronting Roger as his hand, on the edge of the desk, disclosed his clever use of the “take” to leave evidence of his capture.
“Now—study this out if you can!” Tip called out from behind the projector.
He shifted the sprocket-turning handle to bring up the next picture.
“That’s the office, what you can see through the smoke,” Tip declared, “and the smoke comes from behind the desk, and so of course the man standing there has got his back to the lens, and all we have got to go on is his coat and his hair.”
He readjusted the “framing handle” to bring the picture into even more exact alignment with the aperture plate of his projector, so that on the screen every part showed.