ession of one of Hume's boot tracks. Then another flash through
the air, a clatter as a second ball spun across a patch of gravel.

The balls seemed to appear out of the air. Displaying rainbow glints
they rolled in a semicircle about the two men. Rynch stooped, then
Hume's fingers latched about his wrist, dragging his hand away from
the globe. It was only then that he realized that sharp action had
detached his attention from that ball he had wanted to take up.

"Don't touch!" Hume barked. "And don't look at that too closely! Come
along!" He pulled Rynch forward through the yet unclosed arc of the
globe circle.

Hume detoured around the feasting scavengers and brought Rynch with
him at a trot. They could hear behind them the plop and tinkle of more
globes. Glancing back Rynch saw one fall close to the bodies of the
water-cats.

"Wait a minute!" He pulled back against Hume's hold. Here was a chance
to see what effect that crystal had on the clawed carrion eater.

There was a change in the crystal: Yellow now, then red--red as the
few scraps of fur remaining on the rapidly disappearing body.

"Look!"

The pulsating carpet which had covered the dead feline ceased to move.
But towards that spot rolled two more of the globes, approaching the
scavengers. Now the clawed things were stirring, dropping away from
their prey. They spread out in a patch, moved purposefully forward.
Behind them, as guardians might head a flock, rolled three globes,
flushing scarlet, then more.

Hume's hand came up. From the cone tip of the ray tube spat a lance of
fire, to strike the middle crystal. The beam was reflected into the
block of scavengers. Scaled bodies, twisted, crisped, were ash. But
the crystal continued to roll at the same pace.

"Move!" Hume's other hand hit Rynch's shoulder, knocked him forward in
an impetuous shove which nearly took him off his feet. Both men began
to run.

"What--what are those things?" Rynch appealed between panting breaths.

"I don't know--and I don't like their looks. They're between us and
the safari camp if we keep to the river--"

"Between us and the river now." Rynch saw that glittering swoop
through the air, marked the landing of a ball near the water's edge.

"Might be trying to box us in. But that's not going to work.
See--ahead there where that log's caught between two rocks? Run out on
that when we reach there and take to the water. I don't think those
things can float and if they sin