One, swinging the porter off his feet, seized the newcomer's right arm, and, helped by his comrade, endeavored to force him back into the vehicle.

The effort failed, however, so the second desperado drew a knife and plunged it deliberately into the unfortunate man's neck.

It was a fearsome stroke, intended both to silence and to kill, and, with a gurgling cry, its victim collapsed in the grip of his assailants.
Curtis, though almost stupefied by the suddenness of the crime, did not hesitate a second when he caught the venomous gleam of the knife.
Throwing aside his coat, he rushed forward, but he had to cross the whole width of the pavement, and the murderers, realizing that the capture of one or both was imminent, thrust the inert body in his way.
The chauffeur, who must have seen all that happened, had already started the car, the two men scrambled into it, and all that Curtis could do was to run after it and shout frantically to the driver of a taxi coming in the opposite direction to turn his vehicle and block the roadway.
The man understood, but was naturally slow to risk a sharp collision merely at the order of an excited gentleman in evening dress.

He stopped quickly enough, but, by the time his help was available, pursuit was hopeless; the one thing Curtis could do he had done--while running up the street he had deciphered the number of the car, X24-305.
Before Curtis rejoined the dazed hall-porter a small crowd had gathered, and it was difficult to get near the body lying on the curb.
A man picked up an overcoat, and Curtis, cool and clear-headed now, took it, and appealed to him, if he knew where the nearest doctor lived, to run thither at top speed.

The man obeyed him instantly.
"Meanwhile, let me see to the poor fellow," he said.