"Hey!" said Laurie, startled.

Bob, at the doorway, turned. "What's the matter?" he asked.

"Nothing, only-" Laurie took hold of the shelf above the loosened one and pulled. It yielded a little, and so did the other shelves and the rear wall of the cubicle, but it was only a matter of less than an inch.

Bob, at his side, looked on interestedly.

"That's funny," he said. "Push on it."

Laurie pushed, and the tier went back a couple of inches. "Looks like this side was separate from the rest," said Laurie. "What's the idea of having it come out like that?"

"Search me!" answered Bob. "Pull it toward you again and let me have a look." A second later he exclaimed: "The whole side is loose, Nod, but it can't come out because the ends of the shelves strike this part.i.tion board! Try it again!" Laurie obeyed, moving the tier back and forth three or four times as far as it would go. Bob shook his head in puzzlement, his gaze roving around the dim interior. Then, "Look here,"

he said. "The shelves on the side aren't on a level with the back ones, Nod."

"What of it?"

"Nothing, maybe; only, if the back swung out the side shelves wouldn't stop it! See what I mean?"

"Not exactly. Anyhow, it doesn't swing out, so what's the-"

"Hold on!" Bob sprang forward and seized the edge of a shelf in the right-hand tier close to the part.i.tion board, and pulled. It readily yielded an inch, but no more.

"Wait!" Laurie bent and pulled aside the box of jars. "Now!"

Then, as Bob tugged, to their amazement the right-hand tier swung toward them, its lower edge sc.r.a.ping on the cement floor, and the left-hand tier swung with it, the whole back wall of the closet, shelves and all, opening toward them like a pair of double doors!

"Gee!" whispered Laurie. "What do you suppose-"

"Pull them wide open and let's find out," said Bob recklessly.

When the two sides were open as far as they would go, there was an aperture between them some three feet wide. Beyond it was darkness, though, as they gazed, the stones of the cellar wall took shape dimly.

Then Laurie seized Bob's arm.

"Look!" he whispered excitedly. Behind, where the left-hand tier of shelves had stood, was a blacker patch about three feet high by two feet wide, which, as they stared in fascination, evolved itself into an opening in the wall.

"Know what I think?" asked Bob, in low tones. "I think we've found the miser's hiding-place, Nod!"

"Honest? Maybe it's just a-a drain or something. Got a match?"

"There are some over by the furnace. Hold your horses!" Bob hurried out, and was back in a moment and was standing at the opening between the doors with a lighted match held toward the opening in the wall. As the little light grew they saw that the stones of the wall had been removed from a s.p.a.ce of a foot above the floor and three feet high and some two feet wide. Around the opening so made cement had been applied in the form of a smooth casing.

The match flickered and went out, and in the succeeding gloom the two boys stared at each other with wide eyes.

"Would you dare go in there?" asked Laurie.

"Sure! Why not? It can't be anything but a sort of cave underground.

Wait till I get a candle."

"A lantern would be better," suggested Laurie, viewing the hole dubiously.

"That's so, and there's one here somewhere. I noticed it the other day."

Bob's voice came from the cellar beyond, and Laurie heard him walking around out there. Then, "I've got it!" Bob called. "There's oil in it, too! Now we'll have a look!"

Laurie heard the chimney of the lantern squeak as it was forced up and then drop into place again. Then a wan light came toward the closet, and Bob appeared, triumphant and excited. "Wait till I turn it up a bit.

There we are! Come on!"

They pa.s.sed through between the doors, Bob leading, and stooped before the hole in the wall. Bob held the lantern inside, and Laurie peered over his shoulder. "Gee, it's high," whispered the latter.

"Yes, and it isn't a cave at all; it's a tunnel!" said Bob, in awed tones. "What do you say?"

"I'll go, if you will," replied Laurie, stoutly; and without much enthusiasm Bob ducked his head and crawled through. Past the two-foot wall was a pa.s.sage, more than head-high and about a yard in width, stone walled and arched, that led straight ahead farther than the light of the lantern penetrated. The walls were dry, but the earthen floor was damp to the touch. There was a musty odor, though the air in there seemed fresh.

"Where do you suppose it goes to?" asked Bob, in a hushed voice.

"I can't imagine. But it runs straight back from the cellar, and so it must pa.s.s under the garden. Let's-let's go on, Bob."

"Sure! Only I thought we were going to find old Coventry's treasure!"

"How do you know we aren't?" asked Laurie.

"That's so! Maybe he buried it under the garden." Their footfalls sounded clearly on the hard-packed earth floor as they went ahead.

Suddenly Bob, in the lead, uttered an exclamation, and Laurie jumped a foot and then hurried forward to where the other was standing. Beside him, its point buried in the floor of the tunnel, was the lost crowbar!

"What do you know?" gasped Bob. "We're under the farther end of the arbor. That bar came through between those stones up here." He touch the crevice in the arched roof with a finger. "See the dirt it brought down with it? Well, that explains that mystery!"

"Yes, but-where does this thing go to, Bob?"

"Let's find out. It can't go much farther, because the arbor was only about forty feet from the back fence."

But they went that forty feet and perhaps forty more before the wavering light of the lantern showed them a stout wooden door across their path.

Formed of two-inch planking and strengthened with three broad cleats, it was hinged to a frame of concrete. It wasn't a big door, but it looked very formidable to the two boys who stood there and viewed it dubiously in the yellow glare of the lantern; for a big square iron lock held it firmly in place.

"Guess we don't go any farther," said Bob, dryly.

"Maybe the key's here somewhere," Laurie suggested; and, although Bob scoffed at the suggestion, they searched thoroughly but without success.

"We could bust it," Bob said; "only maybe we haven't any right to."

"I don't see why not, Bob. We discovered it. Let's!"

"We-ell, but one of us'll have to go for a hammer or something."

"Sure; I'll go."

"And leave me here in the dark? I guess not!"

"We'll both go, then. Hold on! What's the matter with the crowbar?"

"Of course! I never thought of that! I'll fetch it!" The light receded down the tunnel until it was small and dim, and Laurie, left alone in front of the mysterious portal, felt none too happy. Of course there was nothing to be afraid of, but he was awfully glad when the light drew nearer again and Bob returned. "You hold this," directed Bob, "and I'll give it a couple of whacks."