The runner who was sitting alone in the next booth, leaned out and gazed around the corner into ours.

“Carton!” he shouted in a tone that could have been heard on the street.

The effect of the name of the District Attorney was magical.  For the moment, the crowd fell back.  Before the tough waiters or anyone else could make up their minds just what to do, Kennedy, who had tucked the box into his capacious side pocket, took each of us by the arm and we shoved our way through the crowd.

The head waiter followed us to the door, but offered no resistance.  In fact no one seemed to know just what to do and it was all over so quickly that even Kahn himself had not time to get a glimpse of us through the swinging door.

A moment later we had piled into a taxicab at the curb and were speeding through the now deserted streets uptown to the laboratory.

Kennedy was jubilant.  “I may have almost precipitated a riot,” he chortled, “but I’m glad I stood up.  I think it must have been at the psychological moment.”

At the laboratory he threw off his coat and prepared to plunge into work with various mysterious pans of chemicals, baths, jars, and beakers.

“What is it?” asked Carton, as Kennedy carefully took out the dark leather box, shielding it from the glare of a mercury vapour light.

“A camera with a newly-invented electrically operated between-lens shutter of great illumination and efficiency,” he explained.  “It has always been practically impossible to get such pictures as I wanted, but this new shutter has so much greater speed than anything else ever invented before, that it is possible to use it in this sort of detective work.  I’ve proved its speed up to one two-thousandth of a second.  It may or may not have worked, but if it has we’ve caught someone, right in the act.”

Kennedy had a “studio” of his own which was quite equal to the emergency of developing the two pictures which he had taken with the new camera.

Late as it was, we waited for him to finish, just as we would have waited down in the Star office if one of our staff photographers had come in with something important.

At last Kennedy emerged from his workshop.  As he did so, he slapped down two untoned prints.

Both were necessarily indistinct owing to the conditions under which they had had to be taken.  But they were quite sufficient for the purpose.

As Carton bent over the second one, which showed Kahn in the very act of handing over a roll of bills to the rather anemic man whom his runner had brought to him, Carton addressed the photograph as if it had been Kahn himself.

“I have you at last,” he cried.  “This is the end of your secret ring of jury fixers.  I think that will about settle the case of Kahn, if not of Dopey Jack, when we get ready to spring it.  Kennedy, make another set of prints and let me lock them in a safe deposit vault.  That’s as precious to me as if it were the Black Book itself!”