The Antiquarian Club continued to meet two or three times a week, but for some time the meetings were not enlivened with any further discoveries. Corinne grew quieter and more uncommunicative, Margaret restless and discontented. And as for the twins, now that the excitement had subsided and nothing further on that order appeared to be forthcoming, they became frankly bored with the proceedings of their society and were claimed once more by their basket-ball and tennis-playing companions.

Several afternoons Corinne went alone to the Charlton Street house and sat long with Margaret, going over and over the old account-book story. For neither of them did interest in the matter ever wane. And even though they appeared to have reached an insurmountable barrier, it did not utterly discourage them. The mystery was always there, and the unsolved riddle proved a constant lure.

Then one day Corinne came in, accompanied by the twins, and all seemed in rather high spirits.

"What's the news?" demanded Margaret at once. "Have you discovered something, Corinne?"

"Yes, I have. And while it may not be of any great help, at least it's another link in the chain."

The twins, once more condescending to interest themselves in the affair, exclaimed: "Do tell us about it! We cut a basket-ball match to come home this afternoon!"

"Well, as I said, it isn't much, but it's something. Yesterday I was up at the Forty-second Street Library, browsing around among the old reference-books on New York City history, when I suddenly came across this. You remember, several times Alison spoke about the housekeeper, 'Mistress Phoebe'? Well, I've found out who she is!"

"You have!" they chorused.

"Yes, and I guess it's positive, for two books mention it. She was Phoebe Fraunces, the daughter of Sam Fraunces who kept the famous 'Fraunces' Tavern.' The building, by the way, is still in existence down on Pearl and Broad Streets. It has been restored to look just the way it used to, and is the headquarters of the Sons of the Revolution. Sam Fraunces was a fine man and a great admirer of Washington—"

"Yes, Alison said so!" interposed Margaret, half under breath.

"—and he was afterward the household steward for Washington when he lived in New York as President. One book says Phoebe played quite a part in the plot—preventing it, that is! That's all I found out, but it's interesting."

"It certainly is!" assented Bess, after a moment's thought, "and it's just one more proof that we're on the right track. But still I don't see that it helps very much in finding out what became of Alison, or anything about her!"

"No, it doesn't!" agreed Corinne ruefully. "And that's just where it's so disappointing. But there's this about it. In a puzzle like this, every little bit helps along. Sometimes, what really doesn't seem to amount to anything at all, leads at last to the most important discovery. For instance, that song—'The Lass of Richmond Hill.' That didn't impress us so much when we came across it, yet it really led to all the discoveries we've made. I propose that this afternoon we go over the whole thing again, just as carefully as we can, and see if there isn't some little clue that we may have constantly overlooked. Of course, I've done that by myself dozens of times, and so has Margaret. But four heads are better than one! Who knows but this time we may light on the very thing?"

She was so hopeful and enthusiastic about it that they all settled down to the work, reading over the old diary very slowly and discussing every point that seemed to offer the least suggestion of a clue. They had reached the entry which announced Washington's arrival, and were hotly debating the question whether or not Madame Mortier could be concerned in the plot against him, when suddenly they were electrified by hearing the loud crow of a rooster, coming apparently from the darkness at the far end of the room. (They had been talking and reading by the light of the open fire only.) Every one jumped, and Margaret caught her hand to her heart. But Bess instantly recovered herself, darted across the room, dived behind the curtains, and returned dragging into the circle a grinning, giggling small boy.

"It's Alexander, of course!" was her brief remark. Her captive was certainly an extraordinary-looking youngster! Wiry, and undersized for his age (he was thirteen), he possessed a snub-nose, a shock of brilliant red hair, and a quantity of freckles that literally "snowed under" his grinning countenance. His appearance was rendered all the more remarkable by the fact that he had cut a series of holes in an old, round, soft hat, and his brilliant hair stuck straight up through these in astonishing red bunches. Not one whit did he seem to resent the publicity into which his recent exploit had brought him! Rather did he appear to glory in the situation.

"Aren't you ashamed to be eavesdropping behind the curtains?" demanded Bess, shaking him by his collar, of which she still retained her hold.

Alexander straightened himself and made this cryptic reply:

"I don't get yer! But if yer mean piking off this chinning contest,—no, I ain't!"

At the foregoing remarkable explosion of slang, Corinne suddenly went off into a peal of laughter.

"Oh, Alexander, you're rich!" she exclaimed. "I'm glad to make your acquaintance. Teach me some of that, will you!"

The boy turned to her with an appreciative and understanding twinkle in his eye: "Sure thing! I'll put you wise, any old time!"

But Jess suddenly broke into this exchange of amenities. "Do you girls realize what has happened? Alexander Corwin has been listening to all the proceedings of our secret society, and now he knows just as much as we do! Oh, I could scalp you!" she ended, making a sudden dart at her cousin, who, though still in the grasp of Bess, ducked and evaded her. There had been unceasing warfare between Alexander and the twins ever since he came to reside with them. He teased them unmercifully, and they sought frantically, and always in vain, to retaliate. There seemed nothing they could devise that affected him in the slightest. This, the most recent outrage, constituted to them, therefore, the last straw! Suddenly Margaret intervened:

"Wait a minute! Maybe Alec wasn't really trying to overhear what we said. Perhaps he only meant to give us a scare. How about it, Alec?"

"You got the right dope!" affirmed the young rascal. "D'ye think I'd waste my valuable time listening to the chatter of a lot of Sadies? Nix on that! I just crept in there to give the glad whoop and raise you out of your chairs!"

Alexander never teased Margaret. Her pathetic confinement to her invalid-chair appealed to his rowdy little soul, and between them there had always been an unspoken compact of peace.

"But how much did you hear?" reiterated Jess.

"Well, I couldn't help getting wise to some!" admitted Alexander wickedly, conscious that this same admission was gall and wormwood to the souls of the twins. "Heard a lot of stuff about finding a book in our attic, and George Washington, and a swell guy called Madame something-or-other and some kind of a dinky sapphire thing, and a kid called Alison. Say! she must have been some girl! But, gosh!—you needn't think I wanted to hear it! I was only waiting for the chance to give you the merry ha-ha!"

Dismay fell once more on the circle. Bess had now released him, and he stood upright, jammed his hands in his pockets, and grinned on them with a curious mixture of triumph, defiance, and pure impishness. It was Corinne who became suddenly inspired with a brilliant idea.

"Look here, girls! I vote that we make Alexander a member of the club! What do you say?"

"Gee! I don't want to be!" exclaimed the boy in a panic, making a sudden dive to escape.

"Oh, yes you would, if you knew all about it! Wouldn't he, Margaret? It's just the kind of thing a boy would go crazy about. There's so much adventure in it!"

At the word "adventure," Alexander pricked up his ears.

"What's a lot of girls got to do with adventures?" he inquired skeptically.

"Just wait till you hear!" declared Corinne, and Margaret seconded her with:

"Oh, dear, Alec, you'll just go wild over this! And it ought to have a boy in it, too! Oughtn't it, girls?" But the twins remained obdurate. To allow their declared enemy to share their most cherished secret seemed to them the height of madness. But while Margaret was reasoning with Alexander, Corinne whispered to them:

"You'd better do it, I tell you! He knows too much already, and you don't know but what he might give the whole thing away to Sarah sometime!" And this final argument brought them speedily round to her point of view.

"All right!" they agreed. "Alexander, you can become a member of our secret society if you want to, and Corinne will tell you all about it."

And Alexander, his curiosity now thoroughly aroused, offered no further objection to the honor thus thrust upon him.

Corinne undertook to explain the whole matter to him, showed him their discovery, explained how they had deciphered the code, and then proceeded to read him the translation. His pat, slangy comments on it often moved her to laughter, and when it came to the mention of the song, he immediately wanted to hear it, for—it was Alexander's chief merit—he loved music with the appreciation of a born musician. It happened that among the books Corinne had brought Margaret was the collection of old songs, containing the one in question. She hunted this up now, and, going to the piano, played it over for him, while he stood at her side whistling the air.

"Say, I like that!" he commented when she had finished. "That's a great old tune! The words are a back-number of course, but they go with it fine!" He hummed it over again.

"Isn't it queer!" exclaimed Corinne. "Alexander is the only one who has exhibited the least interest in learning or even hearing that song!"

After this intermission, the story proceeded, the boy growing more and more absorbed with every word. But when it came to the disclosure that Richmond Hill had stood just about where they were now sitting, he leaped to his feet with a whoop.

"Say! Wouldn't that jolt you! Gee! I didn't have any hunch that you girls had a thing like this up your sleeve!" Then, with snapping eyes, he settled down to hear the remainder of the tale. When Corinne had finished, he sat cross-legged before the fire for several minutes, chewing meditatively the cap he had riddled with air-holes.

So long was he silent, that Margaret exclaimed, finally: "Well?" Then he got up, stretched his legs, and inquired: "When you going to have the next meeting of this joint?"

"The day after to-morrow," answered Margaret, who was disappointed that after all he did not seem to have any interested comments to make. "Why?"

"Because," he answered in his remarkable jargon of slang, "you can ring me in on the fest, and—I may have a new piece of dope!"

When the meaning of this remark had dawned on them, they all demanded eagerly: "What? What? Can't you tell us, Alec?"

"Nothing doing—till the day after to-morrow!" he called back as he made a hasty exit down the hall.

And after his departure they all agreed that they had possibly done a rather good day's work in admitting the rowdy Alexander to the Antiquarian Club!