"What—what's your plan, Blake?" yelled Joe into his chum's ear, as he sat behind him on the jolting second saddle of the swaying motor cycle.

"What do you mean?" demanded Blake, half turning his head.

"I mean how are you going to stop that runaway, or rescue those fellows?"

"I haven't thought, yet, but if we can get ahead of the horse we may be able to stop him before he gets to the road-barrier or to the dangerous turn."

"That's right!" panted Joe, the words being fairly jolted out of him. "Head him off—I see!"

"Hold fast!" exclaimed Blake, as the conductor does when a trolley car goes around a curve. "Hold fast!"

There was need of the advice, for a little turn in the road was just ahead of them and Blake intended to take it at almost top speed.

Bumping, swaying, jolting, spitting fire and smoke, with a rattle, clatter and bang, on rushed the motor cycle on its errand of rescue.

"Hark!" cried Joe, close to Blake's ear, "Listen!"

"Can't, with all this racket!" yelled back Blake, for he had opened the throttle to gain a little increase of power. "What's the matter?"

"I thought I heard the horse."

"Hearing him won't do any good," observed Blake grimly. "We've got to see him and get ahead!"

And he turned on a little more gasoline.

While Blake and Joe are thus speeding to the rescue of the men in the runaway, we will take a few moments to tell our new readers something about the boys who are to figure prominently in this story.

Joe Duncan and Blake Stewart were called the "Moving Picture Boys," for an obvious reason. They took moving pictures. With their curious box-like cameras, equipped with the thousand feet of sensitive celluloid film, and the operating handle, they had risen from the ranks of mere helpers to be expert operators. And now they were qualified to take moving pictures of anything from a crowd, shuffling along the street, to a more complicated scene, such as a flood, earthquake or volcanic eruption. And, incidentally, I might mention that they had been in all three of these last situations.

The first volume of this series is called "The Moving Picture Boys," and in that I introduced to you Blake and Joe.

They worked on adjoining farms, and one day they saw a company of moving picture actors and actresses come to a stream, near where they were, to take a "movie drama."

Naturally Blake and Joe were interested at once, and making the acquaintance of Mr. Calvert Hadley, who was in charge of the taking of the play, or "filming it," as the technical term has it, the two boys were given an opportunity to get into the business.

They went to New York, and began the study of how moving pictures are taken, developed from the films, the positives printed and then, through the projecting machine, thrown on the screen more than life size.

The process is an intricate one, and rather complicated, involving much explanation. As I have already gone into it in detail in my first book of this series, I will not repeat it here. Those of you who wish to know more about the "movies" than you can gain by looking at the interesting pictures in some theater, are respectfully referred to the initial volume.

Joe and Blake were much interested in the Film Theatrical Company. My former readers will well remember some members of that organization—C.C. Piper, or "Gloomy," as he was called when not referred to as just "C.C."; Birdie Lee, a pretty, vivacious girl; Mabel Pierce, a new member of the company; Henry Robertson, who played juvenile "leads"; Miss Shay, and others in whom you are more or less interested.

After various adventures in New York City, taking films of all sorts of perilous scenes, Joe and Blake went out West, their adventures there being told in the volume of that name. They had their fill of cowboys and Indians, and, incidentally, were in no little danger.

Afterward they went to the Pacific Coast, thence to the jungle, where many stirring wild animal scenes were obtained, and afterward they had many adventures in Earthquake Land. There they were in great danger from tremors of the earth, and from volcanoes, but good luck, no less than good management, brought them home with whole skins, and with their cases filled with rare films.

Having finished in the land of uncertainty, the work assigned to them by Mr. Hadley and his associates, Joe and Blake had gone for their vacation to the farm of Mr. Hiram Baker, near Central Falls. But their intention of enjoying a quiet stay was rudely interrupted.

For not long after they had arrived, and were resting quietly under a cherry tree in the shade, Mr. Ringold, with whom they were also associated in moving picture work, called them up on the long distance telephone to offer them a most curious assignment.

This was to go to the flooded Mississippi Valley, and get moving pictures of the "Father of Waters" on one of "his" annual rampages.

Of course Blake and Joe went, and their adventures in the flood fill the volume immediately preceding this one.

And now they had returned, anticipating a second session of their vacation. They had brought a motor cycle with which to go about the pretty country surrounding Central Falls.

"For," reasoned Blake, "we haven't much time left this summer, and if we want to enjoy ourselves we'll have to hustle. A motor cycle is the most hustling thing I know of this side of an automobile, and we can't afford that yet."

"I'm with you for a motor cycle," Joe had said. So one was purchased, jointly.

It was on returning from a pleasant ride that our heroes had seen the runaway with which we are immediately concerned. They were now speeding after the maddened horse dragging the frail carriage, hoping to get ahead of and stop the animal before it either crashed into the frail barrier, and leaped into the ravine, or upset the vehicle in trying to make the turn into the temporary road.

"There he is!" suddenly cried Blake. The motor cycle, bearing the two chums, had made the curve in the road successfully and was now straightened up on a long, level stretch. And yet not so long, either, for not more than a quarter of a mile ahead was another turn, and then came the bridge.

"I see him!" answered Joe. "Can you make it?"

"I'm going to!" declared Blake, closing his lips firmly.

Every little bump and stone in the road seemed magnified because of the speed at which they were moving. But Blake held the long handles firmly, and, once the curve was passed, he turned the rubber grip that let a little more gasoline flow into the carbureter to be vaporized and sprayed into the cylinders, where the electric spark exploded it with a bang.

"We—are—going—some!" panted Joe.

"Got—to!" assented Blake, grimly.

On swayed the thundering, rattling motor cycle. The carriage top had either been let down, or some of the supports had broken, and it had fallen, and the boys could now plainly see the two men on the seat. They had not jumped, but they had evidently given up trying to make the horse stop by pulling on the one rein, for the animal was speeding straight down the center of the road.

"We aren't catching up to him very fast!" howled Joe into Blake's ear, and he had to howl louder than usual, for they were then passing along a portion of the road densely shaded by trees. In fact the branches of the trees met overhead in a thick arch, and it was like going through a leafy tunnel.

This top bower of twigs and branches threw back the noise of the explosions of the motor cycle, and made an echo, above which it was almost impossible to make one's voice heard.

"Look out!" suddenly cried Blake. "Hold fast!"

At first Joe imagined that his chum was going to make another curve in the road, but none was at hand. Then, as Blake watched his chum's right hand, he saw him slowly turn the movable rubber handle that controls the gasoline supply. Blake was turning on more power, though now the machine was running at a higher rate than Joe or Blake had ever traveled before.

With a jump like that of a dog released from the leash, the motor cycle seemed to spring forward. Indeed Joe must needs hold on, and as he was not so favorably seated as was his chum, it became a matter of no little trouble to maintain a grip with his legs and hands.

"We—sure—are—going—some!" muttered Joe. But he did not open his mouth any more. It was too dangerous at the speed they had attained. A jolt over a stone, or a bit of wood, might send his teeth through his tongue if he parted his jaws. So he kept quiet.

Ahead of them the carriage swayed and swerved. The horse was a speedy one, but no creature of bone, blood, muscles and sinews can distance a fire-spitting and smoke-eating machine like a motor cycle. The distance was gradually being cut down.

But now, just ahead of them, was the curve, immediately beyond which was the broken bridge, and also the temporary one, shunting off at a sharp angle from the main highway.

"Look out! Hold on!" once more cried Blake, speaking in quick tones.

For a moment Joe wondered at the added caution, and then he sensed what Blake was about to do.

To one side of them stretched a level field. The road made a slight detour about it, just before meeting the ravine, and by crossing this field it was possible for the boys to reach the bridge ahead of the swaying carriage. But at the speed they were now running it was dangerous, and risky in the extreme, to run across the uneven meadow. Blake, however, evidently was going to chance it.

"Hold fast!" he cried once more, and Joe had no more than time to take a firmer grip on the bar in front of him, and to cling with his legs to the foot supports and saddle, than they were off the road, and into the green field. The fence had been taken down to allow for the storage of bridge-building material in the meadow.

"Now we'll get him!" cried Blake, but he spoke too soon. For the motor cycle had not gone ten feet into the uneven field, jolting, swaying and all but throwing off the moving picture boys, than the sound of the explosions suddenly ceased, and the machine began to slacken speed.

With a quickness that was added to by the rough nature of the ground, the motor cycle slowed up and stopped.

"What's the matter?" cried Joe, putting down his feet to support the machine.

"Something's busted—gasoline pipe, I guess!" cried Blake. "Come on! We've got to run for it!"

The accident had occurred only a short distance from the road. Together the two chums, leaping clear of the motor cycle, made for it on the run.

But they were too late. They had a glimpse of the runaway horse dashing straight at the fence barrier.

The next moment there was a splintering crash, and he was through it.

"Oh!" cried Blake.

The thunder of the horse's hoofs on what was left of the wooden approach to the broken bridge drowned his words.

Then the animal, with a leap, disappeared over the jagged edges of the planks. The boys expected to see the carriage and the two occupants follow, but to their intense surprise, the vehicle swayed to one side, caught somehow on one of the king beams of the bridge and hung there.

"Come on!" cried Blake, increasing his speed; "we've got a chance of saving them yet!"