"Well," he said, with his slow smile, "you did it that time."

"We!" cried Betty, her cheeks flushed with excitement and the exhilaration of success. "I should say you did the work while we looked on. Oh, I'm so happy--and so grateful to you."

"But I didn't do anything," he protested, smiling whimsically, as they turned to follow the soldiers and their prisoner. "I simply let the boys do the work while I looked on."

"Goodness! what do we care how it happened as long as it did?" cried Mollie happily. "Maybe now he'll see that he can't run down old ladies promiscuously and get away with it."

"Not with girls like you on his trail," said the sergeant admiringly.

"But what are you going to do with him, now you've got him?" asked Grace, repeating almost word for word the question Mollie had put only a few minutes before. "I suppose we've got to get out some sort of definite charge against him."

"Yes," said the sergeant thoughtfully. "We can put him in the guardhouse up at camp till we have a chance to get the township authorities up here.

And," he added, turning to Betty, "I'd like to have an interview with that old lady of yours, if you can manage it. We'll have to have her evidence, you know."

"Oh, and isn't it lucky?" cried Betty, executing a little skip in her excitement. "She told us only this morning that she was feeling perfectly well again and would go away to-morrow. We were worrying ourselves sick about it, but couldn't think up a single plan to keep her with us. And if she had gone before this happened--" she stopped, overwhelmed by the mere contemplation of the tragedy.

"I still feel as if I were dreaming," said Amy, as they entered the camp gate. "It all happened so suddenly, and just when we were feeling so awfully blue."

"Well, I know I wasn't dreaming," said Grace plaintively, "because in my excitement I dropped two perfectly good candies in the road and forgot to pick 'em up."

They laughed at her, and Betty added whimsically:

"Perhaps it was just as well for your digestion that you did. I suppose you'll have to go to the guardhouse to explain about the prisoner," she rather stated than asked, turning to Sergeant Mullins.

"Yes," he said, adding, with a trace of hesitation: "It won't take long though, and if you don't mind waiting till I get back I'd like to have that talk with the old lady he knocked down. It's necessary to see her as soon as possible."

"Goodness, we don't mind waiting," cried Betty. "And you can't see her too quickly to suit us. We're just crazy to see the whole thing settled--"

"And that brute behind the bars," finished Mollie vindictively.

Sergeant Mullins laughed boyishly, saluted smartly, and turned on his heel to follow the boys who were fast bearing the prisoner to the guardhouse and from there to the just punishment that had been so long in overtaking him.

"Well," said Mollie, as she flopped down on the steps and favored the girls with a beaming smile, "now what have you got to say for yourselves?"

"More in truth than in modesty," twinkled the Little Captain, "I should say that we are pretty good."

"My! don't we love us?" queried Grace, fishing up from her pocket a much-mangled and sadly worn chocolate and calmly inserting it between two very pretty rows of white teeth. "It's really touching--"

"Oh, Grace, how can you think of candies at a time like this?" cried Mollie impatiently.

"Don't know," returned Grace, calmly nibbling. "It's a gift, I guess."

"Gracie, you're an awful goose," cried Betty, hugging her impulsively.

"But I'm so happy, I'll forgive you even that--"

"It's you that ought to be forgiven for calling me names," returned Grace, in an injured tone of voice. "Goodness," she cried, a moment later, pointing a moist and tired chocolate in the direction of the horizon. "Am I mistaken, or is that the stalwart figure of our sergeant approaching in the distance?"

"Oh, it is, it is!" cried Betty, springing to her feet and fairly dancing in her excitement and impatience. "Oh, I can't wait! Why doesn't he hurry?"

As a matter of fact, the sergeant was hurrying very much indeed, for he was almost as eager as the girls to see the old lady and collect the evidence in the case against the motorcyclist.

He was panting as he sprang up the steps toward them and his eyes were bright with antic.i.p.ation.

"I got back as soon as I could," he cried. "Now, if you can take me--"

The girls wasted no time in words, and led him swiftly up the stairs, pausing before Mrs. Sanderson's door.

"What shall we do if she's gone?" whispered Betty, a sudden panic seizing her. Then, without further delay, rapped smartly on the door.

At the answering "come in" they tumbled into the room, followed by Sergeant Mullins. Then it was the second miracle happened!

Mrs. Sanderson started, stared, then rose tremblingly to her feet.

"My Willie boy!" she cried, groping toward him, dazed, unbelieving, incredulous. "It's my boy, my little son--my--baby--"

Then Sergeant Mullins, with a hoa.r.s.e cry, rushed across the room and gathered the little figure in his arms--strong, man's arms that crushed and hurt.

"Mother!" he cried. "Oh, my mother!"

CHAPTER XXIV

MYSTERY EXPLAINED

The girls stared for a moment, dazed, bewildered. Stared at the dark head bent in such pa.s.sionate tenderness over the gray one, stared at the old hands patting the broad young shoulders, tremblingly, joyfully, incredulously, then, with a stifled gasp, turned and fled.

Betty closed the door softly and followed the girls into their own room where they sank down on arms of chairs or tables or the edge of the bed--any place--and went on staring, only this time at each other.

"Betty Nelson," Mollie broke out at last, her eyes dark and wide, her voice awed, "did you ever in your life hear of such a thing?"

"Of course I never did," answered Betty, her lips trembling, her eyes shining and wet. "Not since my fairy-story days, anyway," she added softly.

"But how," Grace demanded, still too dazed to think clearly, "can Mrs.

Sanderson's son be William Mullins?"

"Goodness! how do we know?" returned Mollie, wiping two tears from the end of her nose. "It's all the biggest kind of a m-mystery, anyway. Oh, dear, has anybody got a handkerchief?" as two other tears threatened to make their appearance. "I didn't know I had it in me to be such a goose."

"We seldom do realize our possibilities," drawled Grace, but Mollie was too busy wiping away the traces of her weakness to notice the insult.

"And to think," Amy murmured softly, "that if that old motorcyclist hadn't knocked Mrs. Sanderson down, she would have gone away without finding her son, and the chances are she would never have seen him again."

"I suppose you think we ought to send the motorcyclist a vote of thanks,"

remarked Mollie dryly, recovering herself a little. "If he keeps on knocking old ladies down in the middle of the road and then gets himself arrested, he may be counted on to do a lot of good in the world."

"I don't see how you can say such silly things," Amy began hotly, when Betty broke in pleadingly: