As it flashed by he had a glimpse of a silk-hatted head with gray hair brushed forward of the ears, ruddy complexion, gray moustache and imperial. Alongside was the rusty black bonnet and the brown wig. The man's head was down, and his attitude suggested he was counting something in his lap. The woman's glance followed his.
It was Jack's first glimpse of his quarry, and his hunting instinct was spurred to action. He made a zig-zag dash across the street under the very wheels of motors and trolley cars. The black limousine was out of his reach, but by great good luck he found a taxicab standing by the curb with its engine running.
He flung himself in, crying: "Four times your fare if you can keep that car in sight. A hundred dollars if I am able to arrest the couple in it!"
The taxi leaped ahead. Jack lowered the front window, and leaning forward, pointed out the right car to the chauffeur. In a wild spurt down Forty-Second street they gained half a block on the limousine. They just managed to get across Sixth avenue before the whistle blew. At Fifth the whole line was held up for perhaps half a minute. The press was so great here, Jack could not see the black car, but he had carefully marked its position, about six cars ahead.
When the whistle blew for the East and West traffic to resume they saw it turn down Fifth with a burst of speed. They followed. In and out of the close traffic the big car threaded its way with a wonderful exhibition of sang-froid on the part of the chauffeur. Jack had a good chauffeur too. But a race through such a crowd is purely a matter of luck. They never succeeded in getting within less than five car lengths of their prize. Jack saw that the black car now bore a Georgia license. He made note of the number.
At Thirty-Fourth street the line was held up again. The whistle had just blown, and this promised to be a longer stoppage. Jack jumped out of the taxi, and ran ahead down the line with fast beating heart.
Jack gritted his teeth. "The devil's own luck favors him," he thought. "They must have left the car during the block on Forty-Second."
The chauffeur had not seen him. Jack did not approach him, thinking it better to take a chance of following him to his garage. The line got in motion again, and Jack swung himself aboard his taxi as it passed.