At the mere mention of the name, I felt a sort of start in Miss Lowe, who was seated next to me in the taxicab.  She had quickly recovered herself, but not before I saw that Kennedy’s plan of breaking down the last barrier of her reserve was working.

“She is one of them, too,” Burke nodded.  “I have had my men out shadowing them and their friends.  They tell me that the Annenbergs hold salons—­I suppose you would call them that—­attended by numbers of men and women of high social and intellectual position who dabble in radicalism and all sorts of things.”  “Who are the other leaders?” asked Craig.  “Have you any idea?”

“Some idea,” returned Burke.  “There seems to be a Frenchman, a tall, wiry man of forty-five or fifty with a black mustache which once had a military twist.  There are a couple of Englishmen.  Then there are five or six Americans who seem to be active.  One, I believe, is a young woman.”

Kennedy checked him with a covert glance, but did not betray by a movement of a muscle to Miss Lowe that either Burke or himself suspected her of being the young woman in question.

“There are three Russians,” continued Burke, “all of whom have escaped from Siberia.  Then there is at least one Austrian, a Spaniard from the Ferrer school, and Tomasso and Enrico, two Italians, rather heavily built, swarthy, bearded.  They look the part.  Of course there are others.  But these in the main, I think, compose what might be called ‘the inner circle’ of the ‘Group.’”

It was indeed an alarming, terrifying revelation, as we began to realize that Miss Lowe had undoubtedly been telling the truth.  Not alone was there this American group, evidently, but all over Europe the lines of the conspiracy had apparently spread.  It was not a casual gathering of ordinary malcontents.  It went deeper than that.  It included many who in their disgust at war secretly were not unwilling to wink at violence to end the curse.  I could not but reflect on the dangerous ground on which most of them were treading, shaking the basis of all civilization in order to cut out one modern excrescence.

The big fact to us, just at present, was that this group had made America its headquarters, that plans had been studiously matured and even reduced to writing, if Paula were to be believed.  Everything had been carefully staged for a great simultaneous blow or series of blows that would rouse the whole world.

As I watched I could not escape observing that Miss Lowe followed Burke furtively now, as though he had some uncanny power.

Fortescue’s laboratory was in an old building on a side street several blocks from the main thoroughfares of Manhattan.  He had evidently chosen it, partly because of its very inaccessibility in order to secure the quiet necessary for his work.

“If he had any visitors last night,” commented Kennedy when our cab at last pulled up before the place, “they might have come and gone unnoticed.”