r they
encountered quite a force of Mexicans, guarding the works.

A volley from the bluejackets was returned by a scattering fire
and the Mexicans turned and fled.

But the volley had been sufficient to lose Billie his mount, as
his horse came to his knees with a bullet in his shoulder.

Without waiting to see the cause of Billie's fall any more than
to ask if he was hit, the Jackies pushed on toward the water
works, leaving Billie to look out for himself as best he could
until the work in hand was completed.

"This is sure enough tough luck," was Billie's comment as he
helped the horse to his feet and examined the wound. "It will lay
him up for a week."

He took the horse by the bridle and led him slowly back toward
the Custom House, where he reported to an officer and hunted up
Adrian.

"What had we better do now?" he asked. "I'd like to find a place
to tend to my horse."

"The fighting seems about over," was Adrian's reply, "and I
reckon the horse will be given attention by some one."

"Oh, I don't want to make any trouble, Ad! If nobody objects,
suppose we go hunt a stable."

They were about to leave when a sergeant stopped them.

"You're to follow me to the Captain," he said. "Here," to a
marine who stood by, "take charge of these horses and see that
the lame one is cared for."

"I wonder if they will take our horses away from us?" muttered
Adrian as they followed the sergeant.

"Give it up. I wonder what he wants of us?"

It did not take them long to find out.

"Are you the boys that brought the messages from Lieutenant
Blunt?" asked Captain Rush.

"Yes, sir."

"Will you undertake another mission?"

"With pleasure," replied Adrian.

"Same here, sir," from Billie, "but my horse has been wounded."

"That's bad. However, I guess we can find another."

"Sure, sir. I can borrow Don's."

"Who is Don?"

"He's the other one of us, sir. He is still out with Lieutenant
Blunt."

"Well," said the Captain, "either two of you will do. What I want
is to find out to just what point the Mexican army is falling
back. Do you think you can find out?"

"Sure."

"Very well. My compliments to Lieutenant Blunt and give him this
order. He will pass two of you through the lines. The other can
remain with him. Sergeant, their horses."

Five minutes later, both astride Adrian's horse and leading the
other, they appeared at the outpost and delivered the order.

"Which two shall it be?" laughed the lieu