“Be careful, Monkey,” warned Hugh, as the other prepared to creep away.  “Don’t let them glimpse you at any time, or there may be serious trouble.  They look like an ugly couple of customers.  I suppose you mean to try and get around on the other side of them?”

“Sure thing,” replied the originator of the scheme, “and if I were you, Hugh, I’d make out to hide your bunch, because, believe me, that pair will come whooping along this way like mad pretty soon.”

“Which is what we’ll do right away, Monkey, never fear,” Hugh told him.

Accordingly the four scouts disposed themselves in such fashion that while they would be hidden from view they could at the same time watch whatever took place, and enjoy the fun, if, by good luck, the scheme arranged for the entertainment of the bold hoboes, turned out successful.

The two ragged wanderers were sitting on the stones bordering the ditch or “moat” that surrounded the make-believe ancient castle.  They evidently debated as to the advisability of forcing an entrance to the wonderful mansion, and taking up temporary or permanent quarters there.  Perhaps the idea of spending the coming winter under so magnificent a roof, with frequent excursions around the countryside in search of necessary supplies, engrossed their attention.

Some little time passed away.  The four boys began to show signs of impatience, believing that Monkey Stallings must surely by now have gained the place he had in mind when he left them.

“There, I saw him wave his hand to us from that slit in the stone wall of the tower!” hissed Alec, presently.  “He’s managed to find a way to get inside after all, and now the fun’s going to begin.”

“It’s time, too,” added Arthur, “because the hoboes have made up their minds to try and break into the house.  See, that big chump has picked up a heavy rock, and he acts as if he meant to hurl the same against those stout oaken doors.”

Indeed, that was just what happened.  The collision, however, only resulted in a loud bang, for it would take many hundreds of like blows to do those stout doors any serious damage.  The smaller tramp shook his head dubiously.

“Now they are talking it over again,” whispered Alec.  “The short one is pointing as if he believes they can find a much easier way to get inside than trying to smash the door down.  Hey!  Monkey, better get busy or you’ll find the pair treading close on your heels.”

Hardly had Alec spoken that last low word than a thrilling sound came floating to the ears of the four listening scouts.  None of them could ever describe what it was like; indeed, it seemed to possess a character all its own, and somehow caused the “goose-flesh” to creep over their bodies, even though they knew the origin of the uncanny cry.

The two tramps had jumped back at the first outburst.  They seemed to be staring wildly toward the “donjon tower,” as Alec persisted in calling the round structure at one end of the imitation castle.  Louder and louder grew the racket.  Billy laid a trembling hand on Hugh’s arm as though seeking comfort from personal contact with the scout master.