SURROUNDED BY ENEMIES.

Although the two men had got past Matt, nevertheless he followed them to the end of the passage, arriving just in time to see them disappear through the opening and close the aperture with the slab.

Only two went out. What had become of Sercomb? Had Ferral and Carl captured him—catching him red-handed and so unmasking his treachery?

In any event, Ferral and Carl had proven more than a match for the two miscreants who had stolen in upon them. Thankful that the affair had turned out so fortunately for his friends, although still mystified as to what Sercomb's purpose was, Matt groped his way back along the corridor and mounted the steps.

It was a long flight—much longer than the one at the other end of the passage—and, at the top, Matt was confronted by a blank wall. He ran his hands over it, and, in so doing, must have touched a spring, for a section of the wall slid back and a sudden glow of lamplight blinded him.

"Ach, du lieber!" came the astounded voice of Carl. "Dere vas Matt, py chincher! Vere you come from, hey?"

Matt stepped from the head of the steps into the room in which Ferral and Carl had been sleeping. The panel closed noiselessly behind him.

"Sink me!" muttered Ferral, stepping past Matt to run his hands over the wall. "A nice little trap-door in the wall, or I'm a Fiji!" He whirled around. "How does it come you stepped through it, messmate?"

"Where's Sercomb?" whispered Matt, peering around.

"What's he got to do with this?"

Just at that moment Sercomb's voice came up from below.

"What's going on up there? Anything happened, Dick?"

"Two men came in and made trouble for us!" shouted Matt. "Didn't you hear 'em run down the stairs?"

"No, I didn't hear anybody!" answered Sercomb.

"Take a look around, and we'll see what we can find up here."

During this brief colloquy, Ferral and Carl were staring at Matt in open-mouthed astonishment.

Matt whirled to Ferral.

"Not a word to Sercomb about that hole in the wall," he whispered. "Tell me quick, what happened in here?"

"I was sleeping full and by, forty knots," answered Ferral, in the same low tone, "when I felt myself grabbed. It was dark as Egypt, and I couldn't see a thing. I shouted to Carl, and we had it touch and go, here in the dark. My eye, but it was a scrimmage! Right in the midst of it the fellows we were fighting melted away. I had just got the glim to going when you stepped in on us."

"Wasn't Sercomb in the fight?"

"Why, no. He must have been down-stairs, sleeping like a log. He only just chirped—you heard him."

"Well, Sercomb came into this room with two other men, through that hole in the wall——"

"Is that right?" demanded Ferral, his face hardening.

"Yes, but don't say a word about it. Wait till we find out what his game is."

"How dit you know all dot, Matt?" queried Carl.

Briefly as he could Matt sketched his recent experiences. The astonishing recital left his two friends gasping.

"The old hunks!" breathed Ferral, scowling. "I can smoke his weather-roll, fast enough. What did I tell you about the soft-sawdering beggar?"

Matt stepped into the hall and listened. Apparently, Sercomb was not in the house. Coming back, he pulled his two friends close together so they could hear him without his speaking above a whisper.

"Sercomb has gone out to hurry up the repairs on the big car and get it out of the way. We can talk a little, but we've got to be wary. Don't let Sercomb know anything about this clue I've picked up. We're surrounded by enemies, Ferral, and you're the object of some sort of game they've got on. By lying low, perhaps we can get wise to it."

"Dot shpook auto has dook a hant in der pitzness," murmured Carl, flashing a fearful glance around. "I don'd like dot fery goot."

"This spook business will all be explained, Carl," said Matt, "and you'll find that flesh and blood is mixed up in the whole of it. That white runabout put a shot into one of the tires of that big touring-car, and no revolver ever went off without a human hand back of it. We know, too, how those men got away from that room where they were playing cards. They ran in here, got through the hole in the wall and went out by way of the tunnel. That shot that was fired at you, Dick, and put out the lamp, must have come from this room, just before Sercomb and the others dodged through the wall."

"Sercomb?" echoed Ferral.

"Sure! It's a cinch he was playing cards in that room with the three men. He came here from Denver, and he must have traveled in that big car and brought the others with him."

"Oh, he's the nice boy!" commented Ferral sarcastically. "A fine cousin, that swab is! That phantom flugee is mixing in the game. I wonder if Sercomb has anything to do with that?"

"No. When the phantom auto showed up in the road, Sercomb and all three of the others were scared nearly out of their wits. I'll bet that was the first time Sercomb ever saw it. Besides, the bullet that pierced the tire of the big car came from the runabout. That wouldn't have happened if the runabout was here to help Sercomb's plans."

"Right-o. What kind of a bally old place is this, anyhow? Holes in the wall, tunnels, and all that—it fair dazes me. What could Uncle Jack have wanted of a secret passage?"

"Didn't you tell me that this was an old Mexican house, and that your uncle bought it?" asked Matt.

"That's how he got hold of the place, matey."

"Then it must have come into his hands like we find it. The Mexicans used to build queer houses; I found that out while I was down in Phoenix."

Matt turned away and took a look at the walls. They were wainscoted in cedar, all around. Every little way there were panels, and the entrance to the passage, which Matt had recently used, was by a panel.

"The walls of these adobe houses are always thick," went on Matt, "but these walls are even thicker than common. There's room in this wall for that stairway, and no one would ever suspect the wall is hollow, simply because it's made of adobe."

"How does the door work?" queried Ferral, stepping to the wainscoting and trying to manipulate the panel. "I'd like to know how to get the cover off the blooming hatch; the knowledge might come handy."

Along the wainscoting, about five feet from the floor, were arranged clothes-hooks. Matt, helping Ferral hunt for the secret spring that operated the panel, pulled on one of the hooks. Instantly the panel slid open, answering the pull on the hook with weird silence.

"Chiminy grickets!" murmured Carl, stepping back. "Dot looks like der vay to der infernal blace."

Ferral stepped forward as though he would pass through the opening, but Matt caught his arm and held him back.

"Don't go down there now, Ferral," said he. "When Sercomb comes we want him to find us here. He doesn't guess that I'm next to what he's done to-night, and none of his confederates know it. If we keep mum, the knowledge may do us a lot of good. If we try to face him down with it, we'll only show him our hands without accomplishing anything."

"The sneaking lubber!" growled Ferral. "Why, he berthed us in this room so he and his mates could sneak in on us while we were asleep. But," and here Ferral rubbed his chin perplexedly, "what did they want to do that for?"

"We'll find out," returned Matt, "if we play our cards right."

"You're the lad to discover things," said Ferral admiringly. "I never had a notion you were going to slip out of the house when you left us."

"And I never had a notion what I was going to drop into," said Matt, "I can promise you that. But it is a tip-top clue, and we'll be foolish if we don't use it for all it's worth."

"You've started off in handsome style! Your head-work makes me feel like a green hand and a lubber."

"Dot's Matt, Verral," declared Carl, puffing up like a turkey-cock. "He alvays does t'ings in hantsome shdyle, you bed you. He iss der lucky feller to tie to, dot's righdt. I know, pecause I haf tied to him meinseluf, und I haf peen hafing luck righdt along efer since, yah, so. Be jeerful, eferypody, und oof der shpooks leaf us alone, ve vill all come oudt oof der horn py der pig end. But vat makes Sercomb act like dot?"

"He wants Uncle Jack's property," scowled Ferral, "and I'll wager that's what he's working for."

"But how can he be working for it when he's already got it?" put in Matt. "He claims to have found your uncle, and to have secured the will."

"That's his speak-easy for it. He's a long-winded grampus, and can talk the length of the best bower, but that don't mean that there's any truth in all his wig-wagging."

"Now you're hitting the high gear without any lost motion," said Matt. "Between you and me and the spark-plug, Dick, I don't think he ever found your uncle; and, as for the will, if he really has it, and everything's left to him, what's all this underhand work for?"

A sudden thought came to Ferral.

"Say," he whispered hoarsely, "do you think that sneaking cur could have handed out any foul play to Uncle Jack? I hate to think it of him, but——"

"No," answered Matt gravely, "I don't think——"

He was interrupted by some one coming in at the front door, and stopped abruptly.

"There's Sercomb now," he whispered. "Let's hear what he's got to say for himself. Mind you don't let out anything about my clue. When you had your trouble, I ran in here from the other room and lent a hand."

"Are you up there?" came Sercomb's voice. "I can't find a soul about the place."

From the road the boys could hear the muffled pounding of a motor. And they knew, even as Sercomb spoke, that he was not telling the truth.