"Gentleman in the other cab is hailing you, sir," he said over his shoulder.
"The other cab?"
"The one that has been following us."
I opened the door and glanced behind. A duplicate of my cab stood perhaps fifty feet behind, and from it a familiar figure was slowly emerging, carrying on a high-pitched argument with the chauffeur. The figure stopped to read the taximeter, shook his fist at the chauffeur, and approached me, muttering audibly. It was Davidson.
"That liar and thief back there has got me rung up for nineteen dollars," he said, ignoring my amazement. "Nineteen dollars and forty cents! He must have the thing counting the revolutions of all four wheels!"
He walked around and surveyed my expense account, at the driver's elbow. Then he hit the meter a smart slap, but the figures did not change.
"Nineteen dollars!" he repeated dazed. "Nineteen dollars and—look here," he called to his driver, who had brought the cab close, "it's only thirty cents here. Your clock's ten cents fast."
"But how—" I began.
"You back up to nineteen dollars and thirty cents," he persisted, ignoring me. "If you'll back up to twelve dollars, I'll pay it. That's all I've got." Then he turned on me irritably. "Good heavens, man," he exclaimed, "do you mean to tell me you've been to eight drug-stores this Sunday evening and spent nineteen dollars and thirty cents, and haven't got a drink yet?"
"Do you think I'm after a drink?" I asked him. "Now look here, Davidson, I rather think you know what I am after. If you don't, it doesn't matter. But since you are coming along anyhow, pay your man off and come with me. I don't like to be followed."