out a word Tish turned and ran toward the stream, calling to me to
follow her.

"Tish!" I heard Aggie's agonized tone. "Lizzie! Come back. Don't leave
me here alone. I--"

Here she evidently clutched the revolver involuntarily, for there was a
sharp report, and a bullet struck a tree near us.

Tish paused and turned. "Point that thing up into the air, Aggie," she
called back. "And stay there. I hold you responsible."

I heard Aggie give a low moan, but she said nothing, and we kept on.

The moon had now come up, flooding the valley with silver radiance. We
found our horses at once, and Tish leaped into the saddle. Being heavier
and also out of breath from having stumbled over a log, I was somewhat
slower.

Tish was therefore in advance of me when we started, and it was she who
caught sight of him first.

"He's got a horse, Lizzie," she called back to me. "We can get him, I
think. Remember, he is unarmed."

Fortunately he had made for the trail, which was here wider than
ordinary and gleamed white in the moonlight. We had, however, lost some
time in fording the stream, and we had but the one glimpse of him as the
trail curved.

Tish lashed her horse to a lope, and mine followed without urging.
I had, unfortunately, lost a stirrup early in the chase, and was
compelled, being unable to recover it, to drop the lines and clutch
the saddle.

Twice Tish fired into the air. She explained afterward that she did this
for the moral effect on the fugitive, but as each time it caused my
horse to jump and almost unseat me, at last I begged her to desist.

We struck at last into a straight piece of trail, ending in a wall of
granite, and up this the trail climbed in a switchback. Tish turned to
me.

"We have him now," she said. "When he starts up there he is as much gone
as a fly on the wall. As a matter of fact," she said as calmly as though
we had been taking an afternoon stroll, "his taking this trail shows
that he is a novice and no real highwayman. Otherwise he would have
turned off into the woods."

At that moment the fugitive's horse emerged into the moonlight and Tish
smiled grimly.

"I see why now," she exclaimed. "The idiot has happened on Mona Lisa,
who must have returned and followed us. And no pack-horse can be made to
leave the trail unless by means of a hornet. Look, he's trying to pull
her off and she won't go."

It was true, as we now perceived. He saw his danger, but too late. Mona
Lisa, probably