They were going slower and slower; his blows had no avail now on either beast.  They plodded on.  He turned suddenly in his saddle and saw the three riders spreading fan-shape around them, the one in the center nearest.  He whipped out his gun and fired at the horse.

His own motion made the ball fly wild, but the horseman drew up instantly, and the other edged discreetly away.  And in the ensuing moments the two fugitives gained the base of those cliff-like hills and perceived the dark oblong of a cave mouth.

Down from their exhausted camels they flung themselves, and hand in hand raced to the entrance of the cave.  Coolness and blackness received them.  Their eyes discovered nothing of the tunnel-like interior.

Putting Arlee some distance within, Billy went to the mouth and stood, his gun in his hand, peering watchfully out.  He saw the horsemen draw together for a parley, then one remained on guard while the others circled on separate ways beyond his range of sight.  His fear was that one of them might steal alongside the cave and leap unexpectedly into its very mouth upon him, so with taut nerves he crouched expectant.

Behind him Arlee gave a sudden shriek.

  [Illustration:  “Billy went to the mouth, peering watchfully out”]

CHAPTER XX

A FRIEND IN NEED

He whirled.  “I’ll fire!” he warned, staring into the dark, but his eyes, dazed with the sun, discerned nothing, and in utter ignorance he faced the black possibilities.

“A man—­a hand——­” Arlee gasped incoherently.

“Good Lord, what is it?” said a voice so near at hand that both were startled.

“Burroughs!” ejaculated Billy.  “Is it you—­Burroughs?”

“Yes, it’s I, Burroughs,” the owner of the voice retorted irritably.  “And who the deuce are you?”

“Hill—­Billy B. Hill,” came the jubilant answer, and “Billy be damned!” said the astonished voice, with sudden joviality, and a dark shape strode up to them.  “What on earth are you doing here?  And what about that firing?  Think I was a robber bold?”

“Well, there are three robber sneaks outside that we are hiding from, so I wasn’t sure....  Great Caesar, old scout, but I’m glad to see you!  That puts us out of the woods at last....  It’s the excavator friend,” he added, turning to Arlee.  “Burroughs, I present you to Miss Beecher.  She and I have been having a thoroughly impossible adventure.”

“Let’s have a little light upon these introductions,” returned the excavator, and a click was heard, and a light jumped out overhead, flooding the tunnel-like place with brightness.  In its beams the three stood staring queerly at each other.

Arlee saw a slim, wiry young American, in rough khaki clothes stained with work, a browned, unshaven young man with sleepy looking eyes and a mouth like a steel trap.