uburb, beyond the north wall, Lake noted a
sweat-marked, red-roan horse in the yard of Rosalio Marquez, better
known, by reason of his profession, as Monte.

Straightway the banker reported this possible clue to the sheriff and to
Billy, who was as tireless and determined in the chase as Lake himself.
The other masqueraders had mostly abandoned the chase. He found them on
the bridge of the La Luz sallyport.

"It may be worth looking into," Lake advised the sheriff. "Better send
some one to reconnoiter--some one not known to be connected with your
office. You go, Billy. If you find anything suspicious the sheriff can
'phone to the hospital if he needs me. I'm going over to see how the old
watchman is--ought to have gone before. If he gets well I must do
something handsome for him."

Billy fell in with this request. He had a well-founded confidence in
Lake's luck and attached much more significance to the trifling matter
of the red-roan horse than did the original discoverer--especially since
the discoverer had bethought himself to go to the hospital on an errand
of mercy. Billy now confidently expected early developments. And he
preferred personally to conduct the arrest, so that he might interfere,
if necessary, to prevent any wasting of good cartridges. He did not
expect much trouble, however, providing the affair was conducted
tactfully; reasoning that a dead game sport with a clean conscience and
a light heart would not seriously object to a small arrest. Poor Billy's
own heart was none of the lightest as he went on this loyal service to
his presumably favored rival.

Bicycle-back, he accompanied the sheriff beyond the outworks to the
Mexican quarter. Near the place indicated by the banker Billy left his
wheel and strolled casually round the block. He saw the red-roan steed
and noted the Double Rainbow branded on his thigh.

Monte was leaning in the adobe doorway, rolling a cigarette. Billy knew
him, in a business way.

"Hello, Monte! Good horse you've got there."

"Yais--tha's nice hor-rse," said Monte.

"Want to sell him?"

"Thees ees not my hor-rse," explained Monte. "He ees of a frien'."

"I like his looks," said Billy. "Is your friend here? Or, if he's
downtown, what's his name? I'd like to buy that horse."

"He ees weetheen, but he ees not apparent. He ees
_dormiendo_--ah--yais--esleepin'. He was las' night to the _baile
mascarada_."

Billy nodded. "Yes; I was there myself." He decided to take a