These patches of fire soon joined and increased to a wider and wider swath of flame. The fire traveled slowly westward, but rushed eastward, propelled by the wind.

Wider and wider grew the sea of flame set by the burning blankets. Like Frances, Pratt kept his mount at a fast lope--the speediest pace of the trained cow-pony--nor did he stop until the blanket was consumed to the rawhide knot.

Then he wheeled his mount to look back. He could see nothing but flames and smoke at first. He did not know how far Frances had succeeded in traveling with her "flare"; but he was quite sure that he had come more than a mile from the wagon-trail.

He could soon see a broadening patch of burned-over prairie in the midst of the swirling flames and smoke. His pony snorted, and backed away from the approach-fire; but Pratt wheeled the grey around to the westward, and where the flames merely crept and sputtered through the greasewood and against the wind, he spurred his mount to leap over the line of fire.

The earth was hot, and every time the pony set a hoof down smoke or sparks flew upward; but Pratt had to get back to the trail. With the quirt he forced on the snorting grey, and finally reached a place where the fire had completely pa.s.sed and the ground was cooler.

Ashes flew in clouds about him; the smoke from the west drove in a thick ma.s.s between him and the darkened sky. Only the glare of the roaring fire revealed objects and landmarks.

The backfire had burned for many yards westward, to meet the threatening wave of flame flying on the wings of the wind. To the east, the line of flame Pratt and Frances had set was rising higher and higher.

He saw the wagon standing in the midst of the smoke, Mack Hinkman holding the snorting, kicking mules with difficulty, while a wild little figure on a pony galloped back from the other side of the trail.

"All right, Pratt?" shrieked Frances. "Get up, Mack; we've no time to lose!"

The teamster let the mules go. Yet he dared not let them take their own gait. The thought of that cracked axle disturbed him.

The wagon led, however, through the smoke and dust; the two ponies fell in behind upon the trail. Frances and Pratt looked at each other. The young man was serious enough; but the girl was smiling.

Something she had said a little while before kept returning to Pratt's mind. He was thinking of what would have happened had Sue Latrop, the girl from Boston, been here instead of Frances.

"Goodness!" Pratt told himself. "They are out of two different worlds; that's sure! And I'm an awful tenderfoot, just as Mrs. Bill Edwards says."

"What do you think of it?" asked Frances, raising her voice to make it heard above the roar of the fire and the rumble of the wagon ahead of them.

"I'm scared--right down scared!" admitted Pratt Sanderson.

"Well, so was I," she admitted. "But the worst is over now. We'll reach the river and ford it, and so put the fire all behind us. The flames won't leap the river, that's sure."

The heat from the prairie fire was most oppressive. Over their heads the hot smoke swirled, shutting out all sight of the stars. Now and then a clump of brush beside the trail broke into flame again, fanned by the wind, and the ponies snorted and leaped aside.

Suddenly Mack was heard yelling at the mules and trying to pull them down to something milder than a wild gallop. Frances and Pratt spurred their ponies out upon the burned ground in order to see ahead.

Something loomed up on the trail--something that smoked and flamed like a big bonfire.

"What can it be?" gasped Pratt, riding knee to knee with the range girl.

"Not a house. There isn't one along here," she returned.

"Some old-timer got caught!" yelled the teamster, looking back at the two pony-riders. "Hope he saved his skin."

"A wagoner!" cried Frances, startled.

"He cut his stock loose, of course," yelled Mack Hinkman.

But when they reached the burning wagon they saw that this was not altogether true. One horse lay, charred, in the harness. The wagon had been empty. The driver of it had evidently cut his other horse loose and ridden away on its back to save himself.

"And why didn't he free this poor creature?" demanded Pratt. "How cruel!"

"He was scare't," said Mack, pulling his mules out of the trail so as to drive around the burning wagon. "Or mebbe the hawse fell. Like enough that's it."

Frances said nothing more. She was wondering if this abandoned wagon was the one she had seen turn into the trail from Cottonwood Bottom early in the day? And who was its driver?

They went on, puzzled by this incident. At least, Frances and Pratt were puzzled by it.

"We may see the fellow at the ford," Frances said. "Too bad he lost his outfit."

"He didn't have anything in that wagon," said Pratt. "It was as empty as your own."

Frances looked at him curiously. She remembered that the young man from Amarillo had taken a peep into the Bar-T wagon when he joined them on the trail. He must have seen the heavy chest; and now he ignored it.

On and on they rode. The smoke made the ride very unpleasant, even if the flames were now at a distance. Behind them the glare of the fire decreased; but to north and south the wall of flame, at a distance of several miles, rushed on and pa.s.sed the riders on the trail.

The trees along the river's brink came into view, outlined in many places by red and yellow flames. The fire would do a deal of damage along here, for even the greenest trees would be badly scorched.

The mules had run themselves pretty much out of breath and finally reduced their pace; but the wagon still led the procession when it reached the high bank.

The water in the river was very low; the trail descended the bank on a slant, and Mack put on the brakes and allowed the sure-footed mules to take their own course to the ford.

With hanging heads and heaving flanks, the two cow-ponies followed.

Frances and Pratt were scorched, and s.m.u.tted from head to foot; and their throats were parched, too.

"I hope I'll never have to take such another ride," admitted the young man from Amarillo. "Adventure is all right, Frances; but clerking in a bank doesn't prepare one for such a strenuous life."

"I think you are game, Pratt," she said, frankly. "I can see that Mack, even, thinks you are pretty good--for a tenderfoot."

The wagon went into the water at that moment. Mack yelled to the mules to stop. The wagon was hub deep in the stream and he loosened the reins so that the animals might plunge their noses into the flood. Molly and the grey quickly put down their heads, too.

Above the little group the flames crackled in a dead-limbed tree, lighting the ford like a huge torch. Above the flare of the thick canopy of the smoke spread out, completely overcasting the river.

Suddenly Frances laid her hand upon Pratt's arm. She pointed with her quirt into a bushy tree on the opposite bank.

"Look over there!" she exclaimed, in a low tone.

Almost as she spoke there sounded the sharp crack of a rifle, and a ball pa.s.sed through the top of the wagon, so near that it made the ponies jump.

"Put up your hands--all three of you folks down there!" commanded an angry voice. "The magazine of this rifle is plumb full and I can shoot straight. D'ye get me? Hands up!"

"My goodness!" gasped Pratt Sanderson.

What Mack Hinkman said was m.u.f.fled in his own beard; but his hands shot upward as he sat on the wagon-seat.

Frances said nothing; her heart jumped--and then pumped faster. She recognized the drawling voice of the man in the tree, although she could not see his face clearly in the firelight.

It was Pete--Ratty M'Gill's acquaintance--the man who had been orderly at the Bylittle Soldiers' Home, and who had come all the way to the Panhandle to try to secure the treasure in the old Spanish chest.