yes, the door was locked, and there was no vestige of a key. joyce was suddenly inspired with an idea.

"let's try the keys of the other doors! i noticed that they most all had keys in the locks. perhaps one will fit this." they hunted up several and worked with them all, but not one made the slightest impression on this obstinate lock.

"now isn't this provoking!" exclaimed joyce. "the only room in the house that we can't get in, and the most interesting of all, i'm certain! what shall we do?" cynthia made no reply, but looked at her little silver watch.

"do you know that it's quarter-past six?" she asked quietly.

"mercy, no! we've got to go at once then. how the time has gone!" reluctantly enough they hunted up goliath, who in thorough boredom had returned to his place on the hearth-rug in the big bedroom, gathered together their candles, and found their way to the cellar. cynthia had thoughtfully requested a tin biscuit-box from the grocer, and in this they packed their candles, thus protecting them against the ravages of mice, and left them in the cellar near the window. then they clambered out.

"to-morrow's saturday," said joyce. "in the morning we'll go to the library and look up that book of costumes. after lunch we'll go back to the b. u. h. and finish exploring. there's the attic yet, and maybe we can find that key, too!" with a gay good-by they separated each to her home, on opposite sides of the boarded-up house.

the result of their researches in the library, next morning, was not wholly satisfactory. they found that the most recent fashion of hoop-skirts or crinolines had prevailed all the way from 1840 to 1870, or thereabouts. and while these dates limited, to a certain extent the time of the mysterious happening, it did not help them very much. they felt that they must look for some more definite clue.

that afternoon they entered the boarded-up house for the third time. they found goliath already in the cellar, owing, no doubt, to the fact that bates's pup was patrolling the front yard. so they invited him to accompany them, an invitation which he accepted with arched back and resounding purr. deciding to explore the attic first, they found that a door from the upper hall opened on a stairway leading to it.

at any other time, or in any other house, they would have found this attic of absorbing interest. in its dusky corners stood spinning wheels and winding-reels. decrepit furniture of an ancient date had found a refuge there. antique hair trunks lined the sides, under the eaves, and quaint garments hung about on pegs. the attic was the only apartment in this strange house that received the light of day, for the two little windows like staring eyes were not boarded up. so dim were they, however with dirt and cobwebs, that very little daylight filtered through.

but the attic had no great holding interest at present, since it was evident that it contained no clue to help them in the solution of the mystery. and they soon left it, to search anew every room below, in the hope of coming upon the missing key.

"these old-fashioned keys are so immense that it hardly seems possible that any one would carry one off—far," conjectured joyce. "but why in the world should just that room be locked, anyway? what can be hidden there? i'm wild,—simply wild with impatience to see it all!"

the search for the key was not exactly systematic. neither of the girls felt at liberty to open bureau-drawers or pry into closets and trunks. besides, as cynthia wisely suggested, it was not likely that any one would lock a door so carefully and then put the key in a drawer or trunk or on a shelf. they would either carry it away with them or lay it down, forgotten, or hide it in some unusual place. if it had been carried away, of course their search was useless. but if it had been thoughtlessly laid aside somewhere, or even hidden away in some obscure corner, there was a possibility that they might come upon it.

with this hope in mind, they went from room to room, searching on desks, chairs, and tables, poking into dark corners, peeping into vases and[pg 61] other such receptacles, and feeling about under the furniture; but all to no purpose. they came at last to the great bedroom where were so many signs of agitation and hurried departure, deciding that here would be the most likely field for discovery. goliath had evidently preceded them, for they found him once more curled up on the soft rug before the fireplace. he seemed to prefer this comfortable spot to all others, but he rose and stretched when the girls came in. joyce went straight for the chimney-place.

"i'm going to poke among these ashes," she announced. "a lot of things seem to have been burned here, mostly old letters. who knows but what the key may have been thrown in too!" she began to rake the dead ashes, and suddenly a half-burned log fell apart, dropping something through to the bottom with a "chinking" sound.

"did you hear that?" she whispered. "something clinked! ashes or wood won't make that sound. oh, suppose it is the key!" she raked away again frantically, and hauled out a quantity of charred debris, but nothing even faintly resembling a key. when nothing more remained, she poked the fragments disgustedly, while cynthia looked on.

"see there!" cynthia suddenly exclaimed. "it isn't a key, but what's that round thing?" joyce had seen it at the same moment and picked it up—a small, elliptical disk so blackened with soot that nothing could be made of it till it was wiped off. when freed from its coating of black, one side proved to be of shining metal, probably gold, and the other of some white or yellowish substance, the girls could not tell just what. in the center of this was a curious smear of various dim colors.

"well, what do you suppose that can be?" queried cynthia.

"i can't imagine. whatever it was, the fire has pretty well finished it. you can see that it must have been rather valuable once,—there's gold on it. here's another question to add to our catechism: what is it, and why was it thrown in the fire? whatever it was, it doesn't help much now. if it had only been the key!— good gracious! is that a rat?" both girls jumped to their feet and stood listening to the strange sounds that came from under the valance hanging about the bottom of the great four-poster bed. it was a curious, intermittent, irregular sound, as of something being pushed about the floor. after they had listened a moment, it suddenly struck them both that the noise was somehow very familiar.

"why, it's goliath, of course!" laughed cynthia. "this is the second time he has scared us. he has something under there that he's playing with, knocking it about, you know. let's see what it is!" they tiptoed over and raised the valance.

cynthia was right. goliath was under the bed, dabbing gracefully with one paw at something attached to a string or narrow ribbon. despite the rolls of dust that lay about, joyce crawled under and rescued it. she emerged with a flushed face and a triumphant chuckle. "goliath beats us all!! he's made the best find yet!"

"is it the key?" cried cynthia.

"no, it's this!" and before cynthia's astonished eyes joyce dangled a large gold locket, suspended on a narrow black velvet ribbon. in the candle-light the locket glistened with tiny jewels.

"do you recognize it?" demanded joyce.

"recognize it? how should i?"

"why, cynthia! it's the very one that hangs about the neck of our lovely lady in the picture down-stairs!" it was, indeed, no other. even the narrow black velvet ribbon was identical.

"she must have dropped it accidentally, perhaps when she took it off, and it rolled under the bed. in her hurry she probably forgot it," said joyce, laying it beside the curious disk they had raked from the fireplace. "isn't it a beauty? it must be very valuable." cynthia bent down and examined both articles closely.

"did you notice, joyce," she presently remarked, "that those two things are exactly the same shape, and almost the same size?"

"why, so they are!" exclaimed joyce. "oh, i have an idea, cynthia! can we open the locket? let's try." she picked it up and pried at the catch with her thumb-nail. after a trifling resistance it yielded. the locket fell open and revealed itself—empty. joyce took up the disk and fitted it into one side. with the gold back pressed inward, it slid into place, leaving no shadow of doubt that it had originally formed part of this trinket.

"now," announced joyce, "i know! it was a miniature, an ivory one, but the fire has entirely destroyed the likeness. question: how came it in the fire?" the two girls stood looking at each other and at the locket, more bewildered than ever by this curious discovery. goliath, cheated of his plaything, was making futile dabs at the dangling velvet ribbon. suddenly joyce straightened up and looked cynthia squarely in the eyes.

"i've thought it out," she said quietly. "it just came to me. the miniature was taken out of the locket—on purpose, to destroy it! the miniature was of the same person whose picture is turned to the wall down-stairs!"