ted Symonds, "that is a very important paper you found in
his possession to-night."

"True; but that paper does not furnish us with any clue as to the
identity of the spy in Washington. Schmidt is simply a go-between like
many other sutlers. Probably that paper passed through three or four
hands before it was given to him to carry between the lines."

"Well, there is one thing certain; Baker will make Schmidt talk if any
man can," declared Symonds. "May I ask, Captain, why we are headed for
Poolesville?"

"Because I am looking for the man higher up. I expect to get some trace
of the spy's identity in or around Poolesville."

"You may," acknowledged the Secret Service agent doubtfully; "and again
you may not. Poolesville used to be called the 'rebs' post-office,' and
they do say that word of every contemplated movement of McClellan's
army was sent through that village to Leesburg by the 'grape-vine
telegraph.'"

"Yes, I know," was the brief reply. The two men spoke in lowered tones
as they made what speed they could among the trees. "By the way,
Symonds, has it ever been discovered who it was delayed the despatch
from Burnside, asking for the pontoon bridges?"

"No, never a trace, worse luck; but do you know," drawing his horse
closer to his companion, "I think that and the Allen disaster were
accomplished by one and the same person."

"Those two and a good many others we haven't yet heard of," agreed
Lloyd. "In fact, it was to trace this particular unknown that I was
recalled from service at the front by Pinkerton, and detailed to join
the branch of the Secret Service under Colonel Baker."

"We have either arrested or frightened away most of the informers
inside the city," volunteered Symonds, after a brief silence. "Besides
which, Washington is too well guarded nowadays--two years ago was a
different matter. Now, the general commanding the Maryland border
patrols declares that a pigeon cannot fly across the Potomac without
getting shot."

Lloyd's answer was lost as Symonds' horse stumbled again, recovered
himself, and after a few halting steps went dead lame. In a second
Symonds had dismounted, and, drawing off his glove, felt the animal's
leg.

"Strained a tendon," he growled, blowing on his numb fingers to warm
them. "I'll have to lead him to the road; it is over there," pointing
to a slight dip in the ground. "You go ahead, sir; it's lucky I know
the country."

As the two men reached the edge of the w