Officer Donahue considered the point well taken.

“Ah!” he said, understandingly.  He regarded Archie with an unfriendly eye.  “I know th’ sort well!  Trampling on th’ face av th’ poor!”

“Ya c’n trample on the poor man’s face,” said Officer Cassidy, severely; “but don’t be surprised if one day he bites you in the leg!”

“But, my dear old sir,” protested Archie, “I’ve never trampled—­”

“One of these days,” said Officer Donahue, moodily, “the Shannon will flow in blood to the sea!”

“Absolutely!  But—­”

Officer Cassidy uttered a glad cry.

“Why couldn’t we hit him a lick,” he suggested, brightly, “an’ tell th’ Cap. he resisted us in th’ exercise of our jooty?”

An instant gleam of approval and enthusiasm came into Officer Donahue’s eyes.  Officer Donahue was not a man who got these luminous inspirations himself, but that did not prevent him appreciating them in others and bestowing commendation in the right quarter.  There was nothing petty or grudging about Officer Donahue.

“Ye’re the lad with the head, Tim!” he exclaimed admiringly.

“It just sorta came to me,” said Mr. Cassidy, modestly.

“It’s a great idea, Timmy!”

“Just happened to think of it,” said Mr. Cassidy, with a coy gesture of self-effacement.

Archie had listened to the dialogue with growing uneasiness.  Not for the first time since he had made their acquaintance, he became vividly aware of the exceptional physical gifts of these two men.  The New York police force demands from those who would join its ranks an extremely high standard of stature and sinew, but it was obvious that jolly old Donahue and Cassidy must have passed in first shot without any difficulty whatever.

“I say, you know,” he observed, apprehensively.

And then a sharp and commanding voice spoke from the outer room.

“Donahue!  Cassidy!  What the devil does this mean?”

Archie had a momentary impression that an angel had fluttered down to his rescue.  If this was the case, the angel had assumed an effective disguise—­that of a police captain.  The new arrival was a far smaller man than his subordinates—­so much smaller that it did Archie good to look at him.  For a long time he had been wishing that it were possible to rest his eyes with the spectacle of something of a slightly less out-size nature than his two companions.

“Why have you left your posts?”

The effect of the interruption on the Messrs. Cassidy and Donahue was pleasingly instantaneous.  They seemed to shrink to almost normal proportions, and their manner took on an attractive deference.

Officer Donahue saluted.

“If ye plaze, sorr—­”

Officer Cassidy also saluted, simultaneously.

“’Twas like this, sorr—­”

The captain froze Officer Cassidy with a glance and, leaving him congealed, turned to Officer Donahue.