Billy's time was well occupied. There were so many, many things she wished to do, and so few, few hours in which to do them. First there was her music. She made arrangements at once to study with one of Boston's best piano teachers, and she also made plans to continue her French and German. She joined a musical club, a literary club, and a more strictly social club; and to numerous church charities and philanthropic enterprises she lent more than her name, giving freely of both time and money.

Friday afternoons, of course, were to be held sacred to the Symphony concerts; and on certain Wednesday mornings there was to be a series of recitals, in which she was greatly interested.

For Society with a capital S, Billy cared little; but for sociability with a small s, she cared much; and very wide she opened her doors to her friends, lavishing upon them a wealth of hospitality. Nor did they all come in carriages or automobiles—these friends. A certain pale-faced little widow over at the South End knew just how good Miss Neilson's tea tasted on a crisp October afternoon and Marie Hawthorn, a frail young woman who gave music lessons, knew just how restful was Miss Neilson's couch after a weary day of long walks and fretful pupils.

“But how in the world do you discover them all—these forlorn specimens of humanity?” queried Bertram one evening, when he had found Billy entertaining a freckled-faced messenger-boy with a plate of ice cream and a big square of cake.

“Anywhere—everywhere,” smiled Billy.

“Well, this last candidate for your favor, who has just gone—who's he?”

“I don't know, beyond that his name is 'Tom,' and that he likes ice cream.”

“And you never saw him before?”

“Never.”

“Humph! One wouldn't think it, to see his charming air of nonchalant accustomedness.”

“Oh, but it doesn't take much to make a little fellow like that feel at home,” laughed Billy.

“And are you in the habit of feeding every one who comes to your house, on ice cream and chocolate cake? I thought that stone doorstep of yours was looking a little worn.”

“Not a bit of it,” retorted Billy. “This little chap came with a message just as I was finishing dinner. The ice cream was particularly good to-night, and it occurred to me that he might like a taste; so I gave it to him.”

Bertram raised his eyebrows quizzically.

“Very kind, of course; but—why ice cream?” he questioned. “I thought it was roast beef and boiled potatoes that was supposed to be handed out to gaunt-eyed hunger.”

“It is,” nodded Billy, “and that's why I think sometimes they'd like ice cream and chocolate frosting. Besides, to give sugar plums one doesn't have to unwind yards of red tape, or worry about 'pauperizing the poor.' To give red flannels and a ton of coal, one must be properly circumspect and consult records and city missionaries, of course; and that's why it's such a relief sometimes just to hand over a simple little sugar plum and see them smile.”

For a minute Bertram was silent, then he asked abruptly:

“Billy, why did you leave the Strata?”

Billy was taken quite by surprise. A pink flush spread to her forehead, and her tongue stumbled at first over her reply.

“Why, I—it seemed—you—why, I left to go to Hampden Falls, to be sure. Don't you remember?” she finished gaily.

“Oh, yes, I remember THAT,” conceded Bertram with disdainful emphasis. “But why did you go to Hampden Falls?”

“Why, it—it was the only place to go—that is, I WANTED to go there,” she corrected hastily. “Didn't Aunt Hannah tell you that I—I was homesick to get back there?”

“Oh, yes, Aunt Hannah SAID that,” observed the man; “but wasn't that homesickness a little—sudden?”

Billy blushed pink again.

“Why, maybe; but—well, homesickness is always more or less sudden; isn't it?” she parried.

Bertram laughed, but his eyes grew suddenly almost tender.

“See here, Billy, you can't bluff worth a cent,” he declared. “You are much too refreshingly frank for that. Something was the trouble. Now what was it? Won't you tell me, please?”

Billy pouted. She hesitated and gazed anywhere but into the challenging eyes before her. Then very suddenly she looked straight into them.

“Very well, there WAS a reason for my leaving,” she confessed a little breathlessly. “I—didn't want to—bother you any more—all of you.”

“Bother us!”

“No. I found out. You couldn't paint; Mr. Cyril couldn't play or write; and—and everything was different because I was there. But I didn't blame you—no, no!” she assured him hastily. “It was only that I—found out.”

“And may I ask HOW you obtained this most extraordinary information?” demanded Bertram, savagely.

Billy shook her head. Her round little chin looked suddenly square and determined.

“You may ask, but I shall not tell,” she declared firmly.

If Bertram had known Billy just a little better he would have let the matter drop there; but he did not know Billy, so he asked:

“Was it anything I did—or said?”

The girl did not answer.

“Billy, was it?” Bertram's voice showed terror now.

Billy laughed unexpectedly.

“Do you think I'm going to say 'no' to a series of questions, and then give the whole thing away by my silence when you come to the right one?” she demanded merrily. “No, sir!”

“Well, anyhow, it wasn't I, then,” sighed the man in relief; “for you just observed that you were not going to say 'no to a series of questions'—and that was the first one. So I've found out that much, anyhow,” he concluded triumphantly.

The girl eyed him for a moment in silence; then she shook her head.

“I'm not going to be caught that way, either,” she smiled. “You know—just what you did in the first place about it: nothing.”

The man stirred restlessly and pondered. After a long pause he adopted new tactics. With a searching study of her face to note the slightest change, he enumerated:

“Was it Cyril, then? Will? Aunt Hannah? Kate? It couldn't have been Pete, or Dong Ling!”

Billy still smiled inscrutably. At no name had Bertram detected so much as the flicker of an eyelid; and with a glance half-admiring, half-chagrined, he fell back into his chair.

“I'll give it up. You've won,” he acknowledged. “But, Billy,”—his manner changed suddenly—“I wonder if you know just what a hole you left in the Strata when you went away.”

“But I couldn't have—in the whole Strata,” objected Billy. “I occupied only one stratum, and a stratum doesn't go up and down, you know, only across; and mine was the second floor.”

Bertram gave a slow shake of his head.

“I know; but yours was a freak formation,” he maintained gravely. “It DID go up and down. Honestly, Billy, we did care—lots. Will and I were inconsolable, and even Cyril played dirges for a week.”

“Did he?” gurgled Billy, with sudden joyousness. “I'm so glad!”

“Thank you,” murmured Bertram, disapprovingly. “We hadn't considered it a subject for exultation.”

“What? Oh, I didn't mean that! That is—” she stopped helplessly.

“Oh, never mind about trying to explain,” interposed Bertram. “I fancy the remedy would be worse than the disease, in this case.”

“Nonsense! I only meant that I like to be missed—sometimes,” retorted Billy, a little nettled.

“And you rejoice then to have me mope, Cyril play dirges, and Will wander mournfully about the house with Spunkie in his arms! You should have seen William. If his forlornness did not bring tears to your eyes, the grace of the pink bow that lopped behind Spunkie's left ear would surely have brought a copious flow.”

Billy laughed, but her eyes grew tender.

“Did Uncle William do—that?” she asked.

“He did—and he did more. Pete told me after a time that you had not left one thing in the house, anywhere; but one day, over behind William's most treasured Lowestoft, I found a small shell hairpin, and a flat brown silk button that I recognized as coming from one of your dresses.”

“Oh!” said Billy, softly. “Dear Uncle William—and how good he was to me!”