Thus the big fellow salved his conscience for departing from orders.  But he was so eager to take a hand in proceedings that he felt it would be torture to stay behind.  He was dressed in Von Arnheim’s clothes.  And his build was that of the German aviator.  If he were observed, he would not be suspected.  Even his atrocious Spanish would not betray him, as the German spoke the language almost as horribly as he.

Thus he reasoned to himself, as he strode rapidly after Jack.

When he reached the other side of the grove, and came in sight of the ranch house Bob, as Jack had done, halted in amazement at sight of the splendid structure.

He gazed around him.  Nobody in sight.  Shrubbery intervening prevented him from gaining a clear view of the house.  He started to skirt the bushes.

Meantime, not far away, the conversation between Jack and Muller was nearing a climax.  Approaching the pretended Morales, Muller asked what he had tried to convey in his radio call, explaining it had been so interfered with by another mysterious call as to be non-understandable.  Not knowing Muller was the radio man at the ranch, Jack was nonplussed.  Again he answered that he could not be delayed, and started to withdraw.  Then Muller laid a detaining hand on his arm.

“Keep it to yourself, if you want to,” Muller said.  “But I know something happened at the cave and I have already reported so to the Don.  First I thought you were trying to radio from the cave.  Now here you come by airplane.  There’s—­”

“What do you mean?” growled Jack gruffly, although secretly alarmed.

“I mean there’s something wrong,” Muller said.

Muller still had no suspicion that the man before him was other than he pretended to be.  Merely he was trying to pry into a matter that had aroused his curiosity.  Jack, however, thought he was on the eve of being discovered, and was alarmed.

At this moment Bob, skirting a clump of bushes on the lawn below, came in sight of the two figures and halted.

He saw Jack wrench his arm from the other’s grasp and turn to stride away.  He saw the other raise an arm as if to stay Jack.  And he saw the movement flip Jack’s low-pulled hat from his head.  It was accidental, but to Jack and Bob—­the actor and the observer in this little drama—­it seemed to be by intent.  It is possible Jack still might have saved the day, had he stooped quickly, recovered his hat and clapped it on again before Muller could have seen his features.

As it was, however, Jack thought he was discovered.  And he turned to deal with Muller.  Then, in truth, he was discovered.  Muller cried out in amazement.  Then Jack landed a stinging blow on the mouth which sent the young German toppling to the marble pave.

At Muller’s shout, several rebel sentries, who had been snoozing in the shadows beside the palace, instead of mounting guard, were startled into instant wakefulness.  They came trotting in bare feet, long rifles in hand, and ran up the wide flight of steps.