We saw Miss Winslow safely off on her return trip, much relieved by the promise of the doctor that she might call once a day to see how the patient was getting along.

Warrington was now resting more easily than he had since the accident and Garrick, having exhausted the possibilities of investigation at the scene of the accident, announced that he would return to the city.

At the railroad terminus he called up both the apartment and the office in order to find out whether we had had any visitors during our absence.  No one had called at the apartment, but the office boy downtown said that there was a man who had called and was coming back again.

A half hour or so later when we arrived at the office we found McBirney seated there, patiently determined to find Garrick.

Evidently the news of the assault on Warrington had travelled fast, for the first thing McBirney wanted to know was how it happened and how his client was.  In a few words Garrick told him as much about it as was necessary.  McBirney listened attentively, but we could see that he was bursting with his own budget of news.

“And, McBirney,” concluded Garrick, without going into the question of the marks of the tires, “most remarkable of all, I am convinced that the car in which his assailant rode was no other than the Mercedes that was stolen from Warrington in the first place.”

“Say,” exclaimed McBirney in surprise, “that car must be all over at once!”

“Why—­what do you mean?”

“You know I have my own underground sources of information,” explained the detective with pardonable pride at adding even a rumour to the budget of news.  “Of course you can’t be certain of such things, but one of my men, who is scouting around the Tenderloin looking for what he can find, tells me that he saw a car near that gambling joint on Forty-eighth Street and that it may have been the repainted and renumbered Warrington car—­at least it tallies with the description that we got from the garage keeper in north Jersey.

“Did he see who drove it?” asked Garrick eagerly.

“Not very well.  It was a short, undersized man, as nearly as he could make out.  Someone whom he did not recognize jumped in it from the gambling house and they disappeared.  Even though my man, his suspicions aroused, tried to follow them in a taxicab they managed to leave him behind.”

“In what direction did they go?” asked Garrick.

“Toward the West Side—­where those fly-by-night garages are all located.”

“Or, perhaps, the Jersey ferries,” suggested Garrick.

“Well, I thought you might like to know about this undersized driver,” said McBirney a little sulkily because Garrick had not displayed as much enthusiasm as he expected.

“I do,” hastened Garrick.  “Of course I do.  And it may prove to be a very important clew.  But I was just running ahead of your story.  The undersized man couldn’t have figured in the case afterward, assuming that it was the car.  He must have left it, probably in the city.  Have you any idea who it could be?”