Who could have done the thing—and why?

Carthoris could not hazard even a faint guess. But the thing now was to learn in what portion of the world he was, and then take up his interrupted journey once more.

If it had been the purpose of some enemy to delay him, he had succeeded well, thought Carthoris, as he unlocked the cover of the second dial, the first having shown that its pointer had not been set at all.

Beneath the second dial he found the steel pin severed as in the other, but the controlling mechanism had first been set for a point upon the western hemisphere.

He had just time to judge his location roughly at some place south-west of Helium, and at a considerable distance from the twin cities, when he was startled by a woman’s scream beneath him.

Leaning over the side of the flier, he saw what appeared to be a red woman being dragged across the plaza by a huge green warrior—one of those fierce, cruel denizens of the dead sea-bottoms and deserted cities of dying Mars.

Carthoris waited to see no more. Reaching for the control board, he sent his craft racing plummet-like toward the ground.

The green man was hurrying his captive toward a huge thoat that browsed upon the ochre vegetation of the once scarlet-gorgeous plaza. At the same instant a dozen red warriors leaped from the entrance of a nearby ersite palace, pursuing the abductor with naked swords and shouts of rageful warning.

Once the woman turned her face upward toward the falling flier, and in the single swift glance Carthoris saw that it was Thuvia of Ptarth!

CHAPTER IV.
A GREEN MAN’S CAPTIVE