Some time longer the detective and official talked, and the lamps in the streets were lit when d.y.k.e Darrel left the presence of Mr. Holden, and turned his steps toward a hotel.

"I must send a line to Nell," mused the detective, as he moved along.

"I shall remain a short time in St. Louis, as I may pick up some points here that will be of use to me. I am of the opinion that either this city or Chicago holds the perpetrators of this latest railroad crime."

The detective did not see the shadowy form flitting along not far behind. A man had shadowed the detective since his departure from the railway office. d.y.k.e Darrel, in order to make a short cut, had entered a narrow street, where the lights were few and the buildings dingy and of a mean order.

Moving on, deeply wrapped in thought, the detective permitted his "shadow" to steal upon him, and just as d.y.k.e Darrel came opposite a narrow alley, the shadow sprang forward and dealt him a stunning blow on the head.

The detective reeled, but did not fall. Partially stunned, he turned upon his a.s.sailant, only to meet the gleam of cold steel as a knife descended into his bosom!

CHAPTER VII.

WHAT A HANDKERCHIEF REVEALED.

d.y.k.e Darrel was so dazed from the blow he had received as to be unable to ward off the dirk that was thrust at his bosom by the vile a.s.sa.s.sin, and had not a third party appeared on the scene at this critical moment the story we are now writing would never have been told.

A kind Providence had on more than one occasion favored the daring railroad detective.

Before the point of the knife touched the breast of d.y.k.e Darrel, a swift-flying object sent the deadly weapon out into the middle of the street.

The next instant a man bounded from the shadow of a building upon the would-be a.s.sa.s.sin. There was a short struggle, when the last comer found, that instead of the detective's a.s.sailant, he held a coat in his hands.

The villain had made good his escape.

"Confound you!" greeted the new comer.

"Who was it?"

"I saw him following you, sir, and made up my mind that some villainy was in the wind. I do not know who the villain was. Are you hurt?"

"Not in the least."

Then the two men walked on until a lamp-post was gained. Here the features of each were plainly revealed.

A low exclamation fell from the lips of d.y.k.e Darrel.

"Good thunder, Harry Bernard! how are you? Where in the world did you spring from?"

The detective grasped and wrung the man's hand warmly--a rather slender young fellow, with brown hair and eyes, a mustache being the only sign of beard on his face.

"One question at a time, d.y.k.e," returned the young man with a laugh.

"I mistrusted it was you all the time. It strikes me that you are becoming careless in your old age. Hope you're not in love--THAT makes a fool of a man sometimes?"

"Does it? No, I'm not in any such predicament; fact is, I am wedded to my profession and shall never marry. But, Harry, you haven't answered my questions yet."

"You asked me how I get on; I can answer that by saying that I was never better in my life. I have been across the plains, among cowboys and Indians, and it's given me strong muscles and good health. I arrived in St. Louis this morning. It was the merest chance that placed me in a position to do you a service, d.y.k.e. As I said before, it seems to me that you are getting careless. Just imagine what the result would have been had I not put in an appearance. I have the fellow's coat to show for the adventure."

"True enough. I admit that I was careless," returned the detective, "and my adventure will serve to put me on my guard hereafter. Come with me to my room, Harry, and we will talk over matters in general. I must take the midnight express North, and may not see you again soon, unless you conclude to go on with me."

"I shall remain in St. Louis for the present," returned young Bernard.

He went with his friend to the hotel, however, and soon the two were in the privacy of d.y.k.e Darrel's room.

"Now, then, let us look at that coat." Harry Bernard laid the garment down on the bed, and Darrel began a close examination of the same. It was an ordinary sack coat, with two inside pockets. The detective was not long in going through the pockets.

"Ah!"

The e.j.a.c.u.l.a.t.i.o.n was significant.

It fell from the lips of d.y.k.e Darrel, the detective.

"Now what?" questioned Bernard.

"Look at that."

d.y.k.e Darrel held aloft a handkerchief that had once been white, but which was now dingy with dirt. But this was not the only discoloration. There was a stain on the square bit of linen that was significant.

"What is it?"

"Blood!" answered d.y.k.e Darrel.

Then the detective made a close examination, and made still another discovery--a name in one corner of the rumpled handkerchief.

The keen eyes of the detective gleamed with a satisfied light.

"What have you discovered, d.y.k.e?"

"A clew."

"To what?"

"To the most infamous crime of the century. This handkerchief has the name of its owner stamped plainly in the corner."

"Well?"

"Arnold Nicholson."

"What?"

"That is the name on this bit of linen, which shows that it was once the property of the murdered express messenger. Of course you have heard of the crime on the Central?"

"Yes. It gave me a shock, too. Arnold was a good fellow."

Harry Bernard's face wore a serious look as he took the blood-stained handkerchief from the hand of the detective, and examined it with mournful interest.