"How?" inquired a second voice.
"A bomb, so arranged to explode with the slightest additional pressure, in a—"
"Careful," growled a third man. "Eight fifty-nine would hardly care to have his plans spread all over New York. This cursed shrubbery is so dense that there is no telling who may be near. Come!"
And Carroll, crouched on the outside of the fence which separates the street from the Park, knew that seconds were precious if he was to get any further information. A quick glance down the street showed him that the nearest gate was too far away to permit of entrance in that manner. So, slipping his automatic into the side pocket of his coat he leaped upward and grasped the top of the iron fence. On the other side he could hear the quick scuffle of feet as the Germans, alarmed, began to retreat rapidly.
A quick upward heave, a purchase with his feet, and he was over, his revolver in his hand the instant he lighted on the other side.
"Halt!" he called, more from force of habit than from anything else, for he had no idea that any of the trio would stop.
But evidently one of them did, for from behind the shelter of a near-by bush came the quick spat of a revolver and a tongue of flame shot toward him. The bullet, however, sung harmlessly past and he replied with a fusillade of shots that ripped through the bush and brought a shower of German curses from the other side. Then another of the conspirators opened fire from a point at right angles to the first, and the ruse was successful, for it diverted Carroll's attention long enough to permit the escape of the first man, and the operative was still flat on the ground, edging his way cautiously forward when the Park police arrived, the vanguard of a curious crowd attracted by the shots.
"What's the trouble?" demanded the "sparrow cop."
"None at all," replied Dave, as he slipped the still warm revolver into his pocket and brushed some dirt from his sleeve. "Guy tried to hold me up, that's all, and I took a pot shot at him. Cut it! Secret Service!" and he cautiously flashed his badge in the light of the electric torch which the park policeman held.
"Huh!" grunted the guard, as he made his way to the bush from behind which Carroll had been attacked. "You evidently winged him. There's blood on the grass here, but no sign of the bird himself. Want any report to headquarters?" he added, in an undertone.