For there was a peculiar reverberation from the rocks farther on towards the rock city—a sound that thrilled the listeners through and through.
“Yes, that’s them coming, sir,” said Griggs coolly. “They’re only riding gently, though, and it doesn’t seem as if they know what’s happened to them yet. We shall see them along that curve soon. Now, doctor, will you give your orders about how we are to shoot?”
“Slowly and steadily,” replied the doctor, “and always at the leading men. Listen, Wilton; we three will fire one by one while you all hold your hands to be ready to keep on while we reload, so that they will not be able to advance without seeing their men constantly falling. There must be no excitement, always a careful, steady aim.”
“When shall we begin?” asked Wilton.
“As soon as the first man rides out into the open yonder.”
“Then it’s time to begin at once, sir,” said Wilton sharply, “for here they come.”
“Yes,” said the doctor firmly. “Keep well in cover, every one. Wait till I give the word. I want the leaders to see that the way is barred against their retreat.”
“They’re beginning to see it already,” said Griggs, as about twenty of the Indians rode round the curve into sight, and their quick eyes grasped the fact at once that something had happened at the gap since they passed by.
“Look out! ’Ware arrows,” said Griggs, in a low, deep growl. “Tell ’em, doctor, that they needn’t mind those plaything toys so long as they keep well under cover.”
“We can hear what you say,” said Bourne, and an anxious half-minute passed, before there was a sudden yell, sounding wild and harsh, to echo and re-echo from the mighty walls on either side, while as it went reverberating on from side to side, to die away in the distance, there was another shout, and close upon it the whizz of a flight of arrows, and then a tinkling, splintering sound as they struck against the stones, to snap or glance off, the air just about the barrier seeming for a moment full of the glistening barbed wands.