"The buckets!" he gasped, as he arrived close to the building, one part of which was now fairly covered with the creeping tongues of ruddy fire. "I must use them on it!"

He had to turn the corner of the shed to get to where they stood. And as he did so he ran plump into a figure that was coming toward him. Just in time did Frank dodge a big fist that shot out. And in that second he recognized in the other Shea, the Irishman who had been hired to keep watch of the shed.

"Hold on, Shea!" shouted Frank. "It's me, Frank Bird. Somebody has set fire to the shed! Grab up a bucket of sand and carry it around here. We can put it out yet if we're busy!"

Shea had evidently only been aroused from a sound sleep by the approaching cries of the boy and was still in a daze. He had discovered the fire, and hearing Frank running toward him, supposed that this must be the one who had done the evil deed.

But he had sense enough to do as he was told now, snatching up one of the sand buckets and following the boy. Frank immediately commenced fighting the flames with a vim. He slapped the wet sand at the creeping fire, and wherever it struck there seemed to come a quick abatement of the conflagration. But it was by this time so extended that as fast as he succeeded in knocking it out in one place it cropped up afresh somewhere else.

His ammunition would not last if this kept up.

"Get busy, Shea!" he cried. "Find something and slap at the fire for all you're worth! Fight it, man, fight it!"

As Frank happened to turn his head to learn what the other was doing he saw something that made very little impression on his mind just then, but which had considerable bearing on the matter later.

A light was speeding along the road, heading away from town, and Frank realized that the firebug had seized upon his convenient wheel and was making his escape.

Later on he might figure out the meaning of this movement. Just then he really had no time to give it a thought, no matter if a dozen wheels were concerned. The fire demanded every atom of his attention.