back, Johnny found himself carried backward, still backward, then to one side until a passage had been made.

Through this passage, like a young queen in a pageant, the girl he had rescued rode atop the truck. And by her side, important as a footman, rode Jerry, the monkey.

Hardly had the truck moved to a place of safety than again came the cry:

“Back! Back!”

Once more the crowd surged away from the fire. High time it was, too, for the brick walls, trembling like a tree before its fall, threatened to topple over and crush them.

For a long moment it stood tottering, then instead of pitching headlong into the street, it crumbled down like a melting mass of waxen blocks.

A wail rose from the crowd. Their school was gone. This was followed almost at once by a shout of joy. Their homes were saved, for were not a score of nozzles playing upon the crumbled, red-hot mass, reducing it to blackness and ashes?

Such was the burning of the Shelby School. Who had set this fire? Where was he now? These were Johnny Thompson’s problems. Unless they were speedily solved there was reason to believe that within a month, perhaps within a week, or even a day, other public buildings would be burned to a heap of smouldering ruins. Who was this firebug? What could his motives be?

He thought of the pink-eyed man and of that expression he had surprised on his face. He fought his way back to the store in which he had seen the man. The store was dark, the door locked.

“No use;” he told himself, “couldn’t find him in this crowd. Probably never see him again. Probably nothing to it, anyway. Some people are so constituted that they just naturally enjoy a catastrophe. They’d smile at the burning of their own home. Nero fiddled while Rome burned.”

In this he was partly wrong. He was destined to see this pink-eyed man again, again, and yet again; and always under the most unusual circumstances.

But now his thoughts turned to the child. She had said she had no home. How could that be? What did she know about the fire? Had she been in the building at the time it was set? That seemed probable. Could she answer important questions? That seemed probable, too. He must question her; not now, not here, but in some quiet place. She needed rest and probably food as well. Where should he take her? He had no relatives in the city. His own room would not do. The fire station would be too public and the little girl would be too greatly alarmed to talk well there.

“Mazie,” he thought to himself, “Mazie will take us in.”

Ten minutes later, he and the girl were speeding toward the home of Mazie, the girl pal of Johnny’s boyhood days.

It was a very much surprised Mazie who at last answered Johnny’s repeated ringing of her bell, but when she saw it was Johnny who called she at once invited him to join her in the kitchen, the proper place to entertain a friend who calls at three in the morning in a grimy fireman’s uniform.

Mazie was a plump young lady. The bloom on her cheeks was as natural as the brown of her abundant hair. A sincere, honest, healthy girl she was—just the kind to be pal to a boy like Johnny.

“Mazie,” said Johnny as he entered the kitchen and sat down to watch her light the gas, “this is a little girl I found. I have a notion she’s hungry—are you?” he turned to the girl.

The girl nodded her head.

“What’s your name?”

“Tillie McFadden.”

It was a strange story that Tillie McFadden told over Mazie’s cold lunch and steaming cocoa. She truly had no home. Weeks before—she did not now how many—her mother had died. Neighbors had come in. They had talked of an orphan asylum for her. She had not known quite what that was, but it had frightened her. She ran away. A corner newstand man had allowed her to sell papers for him. With these few pennies she had bought food. For three nights she had slept on a bed of shavings in a barrel back of a crockery store.

Then, while prowling round a school house at night, she had discovered a basement window with a broken catch. She had climbed in and, having made her way to the upper story which was used as a gymnasium, had slept on wrestling mats. Since this was better than the barrel, like some stray kitten that has found its way out of the dark and the cold, she had made her home there.

“And now,” she exclaimed, her eyes growing suddenly wide with excitement, “it’s all burned up!”

“What time did you go to sleep to-night?” Johnny asked.

“I—I think I heard the tower clock strike eleven.”

“And were you up there all the time?”

“No, down in the office mostly.”

“The office?” Johnny leaned forward eagerly. That was where the fire had started.

“Yes.”

“What were you doing in the office?”

“Looking at picture books. Lots of them down there, and I could read by the light from the street lamp.”

“But didn’t you hear any sound; smell smoke or anything?”

“N—o,” the girl cast upon him a look of puzzled eagerness. It was plain that she wished to help all she could.

Further questioning revealed the fact that she had nothing more of importance to tell. The sound of fire gongs and sirens had wakened her. She had gone to the window to look down. Then, realizing her peril, she had dashed for the head of the stairs, only to find her way cut off by flames and smoke. She had returned to the window. The rest Johnny knew as well as she.

After the child had been put to sleep on a couch in the living room, Johnny and Mazie sat long by the kitchen table, talking. Johnny told of his new task and of his hopes of capturing the firebug.

“Of course,” he said, “the police and fire inspectors are working on it. They’ll probably solve the mystery first. I hope they solve it to-morrow. No one wants the city’s buildings burned and lives endangered by fire. But,” he sighed, “I’d like to be the lucky fellow.”

“I wish you might,” said Mazie loyally. “I—I wish I could help you. Oh, Johnny, can’t I? Couldn’t I come down and stay awhile in that strange central station where all the alarms come in? It must be fairly bewitching.”

“I guess there’d be no objection to that,” said Johnny thoughtfully. “As for your helping me, I’ll welcome all the help I can get. Looks like I was going to need it. Didn’t get a clue except—well, there was the pink-eyed man.”

“The pink-eyed man?” Mazie exclaimed in amazement. “Who was he?”

Johnny told her about the man in the store. “Probably not much to it,” he added at the end.

“But, Johnny,” said Mazie suddenly, “if Tillie was in the office until nearly eleven o’clock, how could the fire, which started near the office, have gotten going so strong before the firemen arrived? It takes some time to start a big blaze, doesn’t it?”

“Yes, it must,” answered Johnny thoughtfully. “Doesn’t seem that the firebug could have accomplished it in an hour. It might have been—” he paused to consider—“it might have been set by a mechanism such as is sometimes used on a time bomb, but how could it have been gotten in during the day? Tell you what!” he exclaimed, “I’ll go back there as soon as the fire cools and look about in the ruins. That side of the wall fell outward. If a mechanism was used, its remains should still be there. I may discover something.”

He did go and he did discover something. At the time of this