Suddenly a great cry arose from the roofs of the temples; a cry of alarm and warning that, taken up from point to point, ran off to the east and to the west, from temple, court, and rampart, until it sounded as a dim echo in the distance.

The great Thark's long-sword leaped from its scabbard; Thuvia shrank shuddering to my side.

CHAPTER VI

THE BLACK PIRATES OF BARSOOM

"What is it?" I asked of the girl.

For answer she pointed to the sky.

I looked, and there, above us, I saw shadowy bodies flitting hither and thither high over temple, court, and garden.

Almost immediately flashes of light broke from these strange objects. There was a roar of musketry, and then answering flashes and roars from temple and rampart.

"The black pirates of Barsoom, O Prince," said Thuvia.