Although there was not much more than an hour of daylight left, the two friends put off their mathematical researches and spent a little time in exploring the ruins of the house. David opened the heavy, charred door of his own refuge and showed Betsey the remains of the room inside with the fragments of a brick staircase that had once wound upward above it.

“This end of the house was not destroyed at once, I think,” he said, “and I believe a good deal of the furniture was got out of it, things that you can still see at the cottage. The roof fell after a day or two and carried the walls with it, so that there are some relics left in the ruins still. This little room under the stairs must have been a den belonging to Miss Miranda’s brother Ted, for I found a pair of spurs and a rusty rifle, a melted silver cup, and some such things here. Beyond must have been the library and a conservatory behind, at least there are mountains of broken glass beside that wall.”

From here, then, had been rescued the toy-cupboard and such pieces of heavy mahogany furniture as were still in use in the cottage and which stood out in such strong contrast to the very plain chairs and tables of painted pine that filled the rest of the Reynolds’ abode. The ivy that had once climbed the high walls, that had crept around the leaded windows and festooned the pillared doorway, now spread its mats of green and its slim, rose colored tendrils over the desolate ruins and covered what it could. Broken pictures still showed half buried under bricks and plaster, while a mirror leaned crookedly against a wall, showing fantastic patterns of shivered glass.

“This must have been the kitchen,” David went on as they progressed farther. “Be careful how you climb about, these old walls are none too solid.”

He himself, however, went clambering up heedless of precaution, his only thought being, apparently, that harm might come to Betsey.

“That place beyond I’ve never explored,” he said; “wait here a minute until I get to the top of that ridge of bricks. The weight of both of us might make it begin to slide.”

“Don’t,” she objected, “it doesn’t look safe at all. Can’t you go to the other—”

He had left her protests unheeded and had clambered half way up the slope of broken débris, when she saw it begin to tremble under his feet, then suddenly give way and carry him down out of her sight. She ran to the edge to see, squeezed through the cleft made by the collapse of the brick-heap and slid down after, to find David, a trifle scratched and with his red hair full of brick-dust, standing gazing about him with untroubled interest.

“This must have been the end of the house where the fire started,” he commented. “See how much blacker the walls are and how even the bricks are burned. And look, that must be a part of one of the chimneys still left standing: you can see that the lightning struck it and split it to the very base. I wonder, with all the frost and rain since the fire, that it hasn’t fallen long ago. I don’t quite understand what this room is. It seems to have been away from the house and on a lower level.”

Elizabeth balanced on the edge of a stone and looked at the confusion about her, where rusty heaps of metal and coils of wire lay amid the other rubbish.

“It must have been Mr. Reynolds’ workshop,” she suggested, “and see, even those steel bars are melted together. The fire must surely have been hottest just here.”

“I believe you’re right.” David was picking his way about looking at the broken engine parts and the melted bits of steel. “I suppose he was working even then on that same invention. I think it ought to be a very great thing when it is done.”

“I think,” began Betsey, “that—oh, look, look!”

She stood transfixed with dismay, staring at something behind him. David gave one glance and knew better than to pause and look again.

“Quick,” he cried, and, seizing her hand, dragged her, almost headlong, across the open space and up another slope of sliding bricks.

The old chimney, split by the lightning and weakened by fire and frost, was ready to tumble at the slightest shock and had received its final impetus from the collapse of the neighboring wall. As Betsey looked at it the whole mass was tottering and, but for David’s quickness, would have engulfed them both. As it was they were nearly smothered by the cloud of dust and crumbled mortar. Blinded and breathless, they scrambled out of the hollow to safety. David’s dusty face had not lost its cheerful smile, but he spoke with great decision.

“I was very wrong to let you go in there,” he said. “I might have seen that the whole place is shaky and that the walls have been collapsing, little by little, for years. We will not go near this end of it at least, again.”

Elizabeth knelt by the pool to wash the dust from her face and hands, while David, having done the same, went to fetch his geometry book.

“Now,” he said, sitting down by her with something of a sigh, “we really must, I suppose, begin on that tiresome pyramid.”

They had a gay session there under the trees before the light began to fail, while each, by instructing the other, succeeded in mastering all former difficulties. In the end they fell to firing rapid questions at each other, Betsey trying to trip David in his fluent statement of the theorem, he in turn lying in wait for her on obscure points of the proof, until neither could be shaken from the thoroughness with which knowledge was now entrenched.

“How lucky it is,” said Betsey, putting down the book and leaning back with her elbow on the rim of the pool, “that each of us stuck in a different place! I hope it will often be that way and that we can help each other more. Now why—” her method of finding things out was apt to be by blunt questioning, a habit she could not easily put aside, “why are you getting ready for college all alone when it is so much easier to do it by going to school?”

David stretched his long legs in the grass and looked fixedly down into the water.

“I was nearly ready to go two years ago,” he explained, “but I left school instead and began to work, since I was too young to go to war. I have no father and things were not going very well with my mother and me while the war lasted, and besides every pair of hands was needed for the extra labor. Now that peace has come, our affairs are better again and I could go to college next autumn, except that there are some things I still have to learn. I took this place with my uncle because I knew the work would only last through the summer and then would leave me free. I have a cousin who is a professor over at the college and who helps me with my work, but I don’t have time to go to him often.”

Elizabeth was thinking, as she sat looking into the water, of how she would feel if further education became suddenly as complicated for her as it was for him. The knowledge of his difficulties tended to arouse her own flagging zeal, so that she began to feel that obstinate pyramids and elusive pirates could not really stand in the way of true determination. As she sat reflecting, footsteps approached along the grassy path and Miss Miranda’s voice sounded behind them.

“I have been looking for you everywhere,” she said. “Dick has been trying to tell me about his adventures, but has only succeeded in convincing me that it was a very desperate affair. Poor battered bird, he will not sit on the wall and call out challenges to other crows soon again. I have invited myself to have supper with you here beside the pool, while you tell me all that has happened.”

She set down the basket that she had been carrying and began to spread a table cloth on the grass.

“Michael is feeding Dobbin,” she said, “and I have telephoned to Betsey’s house, so that all that you have to do is to sit down and eat.”

The suggestion was adopted with alacrity, for the appetites of the two were keen, and their own evening meals seemed far away. Amid much mirth was told the tale of poor Dick’s misfortunes, of his headlong flight from his enemies and of the amazement of the pigeons on whose hospitality he had so unceremoniously thrust himself. Of her talk with the farmer’s wife, Betsey did not say so much, only delivered her messages and accounted for the eggs.

“I thought I would drop them a hundred times,” she said at the end. “I never knew that eggs could grow so heavy.”

She sat lazily on the grass, feeling rested and content, unmindful for any further exertion than to dabble her fingers in the quiet pool. A shimmering band of sunset light dyed the opposite half of the basin as though the water had been set on fire. Miss Miranda, leaning comfortably against a tree, had taken out her knitting.

“There is something wrong with Michael to-night,” she observed as she clicked the needles in and out. “He is sitting on the bench by the gate staring straight before him and not even smoking his pipe. When I asked him what was the matter he only growled out that a black cat ran across his path last night and that trouble was bound to follow. I suppose he is reciting spells to himself, to drive off the evil. Certainly there was no use in talking to him.”

Elizabeth was looking up at the ruined house, trying to imagine how it had seemed, with lights in the windows, with fires on its deserted hearthstones, with all the warm brightness of home shining through its open doorway. Miss Miranda must have been thinking, with far greater and more painful clearness, of much the same thing.

“I used to believe,” she said suddenly in midst of a silence, “when I came home from school and crossed the lawn to that side door, that burned, marred door in the wall that is the only one left, that it opened on the dearest place in the world. The big, black cherry tree that grows beside it used to spread such a cloud of white blossoms every spring! I always thought, when I heard people talk of the narrow gate of Heaven, that it must look just like my little dark door under the blooming cherry tree.”

She moved over to sit by Elizabeth at the edge of the pool.

“It is not easy to come home to an empty, silent house that is not really home,” she went on. “No one knows that better than I, my dear, or would like more to make it up to you.”

Betsey moved closer and smiled up at her gratefully.

“You do make it up to me,” she said.

David, who was lying stretched out at Miss Miranda’s feet was busy at a task of his own. It seemed that he was a persistent boy who would never lay aside a piece of work until every detail that he could think of had been added to make it complete. He had fetched some clay from the far end of the garden and was modeling the frustum of a pyramid and those three confusing portions into which it could be divided. Betsey watched him idly, quite content that he should have the labor and she the benefit. He demonstrated them with a flourish on the smooth rim of the pool.

“You make it so clear,” remarked Miranda, “that I almost understand it myself, although I had forgotten it ten years ago.”

“Your father must know all about such things,” David said rather wistfully; “it discourages me to think of how much he knows. Do you suppose he would care to have—to have any one help him in his shop, just to sharpen tools and screw bolts and run errands?”

“He needs some one like that very greatly,” Miss Miranda answered. “As a rule he likes to do his work alone for fear the news of what he is trying to make will get about before he is ready. But I know you well enough to be certain that you will give away no secrets.”

Elizabeth drew her dripping hand from the water and took up one of the pyramids.

“I never thought I could understand it so clearly,” she said, “and now if I could only remember about the Barbary pirates and the merchant marine, I really could be almost sure of going to college.”

“Barbary pirates?” repeated Miss Miranda. “I happen to know something of them, myself. How do they come to trouble you when they have all been dead so long?”

“Oh, I just don’t seem to be able to remember when they lived, or what they did,” Betsey sighed. “They seem to come in that dull middle period in the history, between the Revolution and the Civil War, when nothing particular ever seemed to happen and most of the Presidents were men whose names you never heard before. It’s all very difficult.”

“Do you remember,” returned Miss Miranda, “that little green tree that you saw in my toy cupboard, the first day that you came? It was put there by my great-grandfather, who fought against those self-same pirates and helped to put an end to their wrongdoing. If I should tell you how he came into possession of the tree, I believe you could remember better what happened in those early days and how America built up her shipping, that merchant marine about which I have heard you groan. Would you like to hear?”

“We would,” answered the two in a single breath.

“And may I go and bring the tree to show David?” Elizabeth asked. She scarcely waited for permission but was off down the path having quite forgotten her former weariness.

Michael was sitting on the bench as Miss Miranda had said, and would not even respond to her greeting as she passed. He had been so friendly of recent days that she stopped, surprised, and turned back to question him.

“What is the matter Michael? Is it really the black cat that troubles you so?”

“Matter enough,” he returned morosely, “even without the black cat. There has been trouble brewing for long and I am thinking it is about to break.”

“But why? What trouble? What makes you think so?” Betsey pressed her questions anxiously. But his answers were most unsatisfactory.

“Oh, just trouble. And how do I know it is coming soon? I feel it in my bones like.”

He would say no more and she was forced to go about her errand. As she crossed the lawn by the house she saw that the workshop door was open to the warm night air and that Mr. Reynolds was as busy as ever inside. It made a quaint picture, the shadowy room, the brilliant circle of light, the old man’s intent, intelligent face bent over his work, the black crow sitting immovable as a statue on the corner of the table. A pleasant noise of quietly whirring wheels came out of the door, a peaceful, comfortable song that mingled with the cheery chirp of a cricket in the grass. It was such a happy, untroubled scene. No presentiment of evil could be lurking that night in any bones, but Michael’s.

When Elizabeth returned with the little tree, David was as entranced with it as she had been. It stood on the edge of the basin in the last of the failing twilight and, in its airy grace of form and glittering of jade and jewels, it seemed scarcely a thing of reality at all. Miss Miranda laid her knitting on her knee for the light was gone at last. The sunset colors had faded in the water and the fireflies were beginning to wink and shine in the shadows of the pine trunks as she began.