“What is it?” cried Nick.

“The man who was in room B!” exclaimed Gaspard.  “I am sure of it!”

At that instant a downtown train rushed into the station, cutting off Nick’s view.

And a half-second later an uptown train pulled in on their side.  Nick pushed open a gate before the train had fairly stopped.  He dragged Gaspard after him.

The gateman tried to stop them, but Nick pushed the fellow in the car so violently that he sat down on the floor.

Then the detective pulled the other gate open, and, still dragging Gaspard, sprang down in the space between the tracks.

The other train was just starting.  Nick leaped up and opened one of the gates.

Gaspard stood trembling.  Excitement and terror rendered him incapable of action.

Nick reached down, and, seizing the man by the shoulders, lifted him up to the platform of the car as if he had been a child of ten.

“Look back,” cried the detective, pushing Gaspard to the other side of the car.  “Is your man still at the station?”

Two or three men were there, having, apparently, just missed the train.

It seemed possible that the criminal—­if such he was—­had seen Gaspard point, and had been shrewd enough not to board the car.

But Gaspard looked back and declared that his man was not there.

“Good,” said Nick.  “He must be on the train.  We have him sure.”

CHAPTER III.

John Jones.

“I want you!” whispered Nick.

How many luckless criminals have been startled by those words!  How many have seen the prison or the gallows rise before them at the sound!

In this case, however, the words seemed to produce less than the ordinary effect.

The man to whom they were addressed turned suddenly toward the detective, but did not shrink or tremble.

“I beg your pardon,” said he; “I didn’t quite understand what you said.”

The man’s coolness made Nick even more in doubt about Gaspard’s identification.

After boarding the train they had walked through it hurriedly, and in the car next the engine Gaspard had clutched Nick’s arm, whispering: 

“There is your man!”

The person indicated was well-dressed, rather good-looking, and about thirty-five years old.  There was nothing particularly striking about his appearance.

It would have been easy to have found dozens of such men on lower Broadway any day.

Nick feared a mistake.  But Gaspard was sure.

“I never forget a face,” he said.  “That is the man whom I saw coming out of room B. That is the murderer.”

The man was standing up and holding on to one of the straps.  His profile was turned to them.

Nick waited until he turned and showed his full face.  The detective was bound to give Gaspard every chance to change his mind.