"Exactly. I don't want to interrupt your amusement, Herr Wonckhaus, but you will wait until my party has passed. A few moments will suffice. If you loose another rock till then, I shall throw you after it!"
Frank's nerves were tingling, but he spoke as quietly as if he was announcing the merest matter of fact. The German recognised at a glance that it was no empty threat, and his Kurd looked by no means comfortable under the menacing attitude of Ali, who had now joined them. Meanwhile, Joseph had come up with the carriers.
"Come straight through, Joseph," called Frank, "and lead my horse and Ali's. Go forward: we will overtake you."
As the mules were passing through the narrow gap that remained between the obstacles on the track, Abdi's party came in sight at the southern end of the defile half a mile distant.
"Now, my good sir," said Frank, as the last of his mules emerged from the gap, "we will help you to complete your amusing work. Ali, shove these stones down as fast as you can, and get your countryman to assist you."
Ali grinned and hurled a threat at the other Kurd; the two pushed the stones down the slope one after another in quick succession, while Frank, taking out his revolver, stood guard over the German. In a few seconds the track was wholly blocked up.
"We have saved you the trouble, Herr Wonckhaus," said Frank. "Good-day."
With Ali he slipped down to the track, ran after his party, sprang to the saddle, and was already some distance ahead and rounding a corner when Abdi and his cavalcade rode up. The Kurd leapt from his horse, scrambled up the barrier, and in his rage and disappointment fired after the retreating figures before Wonckhaus, uneasy about future developments, could check him. The shot flew wide, and Frank rode on.
To clear a way for the pursuers' horses would probably consume at least half an hour, an interval long enough to allow the party to reach the outskirts of a settled district where an open attack upon them would be dangerous. And Frank knew very well that Wonckhaus could hardly afford to be publicly associated with a manifest act of brigandage. Thinking over the circumstances of the trap from which he had escaped, he surmised that the German had intended the party to be intercepted by the Kurds several miles behind, and that he had gone ahead in order to arrive at Erzerum in time to establish a clear alibi if there should be any suggestion of his connection with the contemplated attack.
"A lucky thing for us you discovered that scout, Ali," said Frank. "I owe something to your eagle eye."