alf-emptied gallon canteen, caught up the small
one and her own rifle, and started off in lead of the pony. Her easy
swinging stride, though seemingly unhurried, covered the ground faster
than the pony could walk. Every little while the animal had to break
into a jog to catch up with her.

At the far end of the scattered mesquite growth Carmena edged off to the
left, down a shallow wash that brought them around to the west side of a
ridge. Under cover of the gaunt earth-rib of worn rock she headed north,
straight for the distant towers of Triple Butte.

The deceptive green of occasional palo-verde bushes now gave place to
the columns of the giant sahuaro. The fluted, leafless stems of these
high-towering cactus candelabras bristled with fierce thorns, yet each
was crowned with the glory of a gorgeous foot-wide blossom.

Over the loose hot sand, amidst this shadeless mockery of a forest,
Carmena swung steadily along at her graceful stride. Her movements
seemed as lacking in effort as the lope of a coyote or the bound of a
cat. Lennon would not have realized how greatly she was exerting herself
had he not seen how frequently she drank from her canteen.

No one of white blood, however thoroughly inured to thirst, can walk
fast under the blistering sun, in the bone-dry air of the desert,
without need of much water. Lennon, though riding, was no less parched
than the girl. He was fresh from a moist climate, and the Gila monster
poison had put him into a feverish condition. Hard as he tried, he could
not resist drinking. His canteen was emptied even sooner than
Carmena's.

This was little past mid-afternoon. They had left the sahuaros behind
and were coming down among widely scattered salt bushes to the border of
an utterly barren alkali flat. For the first time since the stop in the
mesquite, Carmena halted her quick advance. But it was not to rest. The
feverish crimson of Lennon's face sobered her reassuring smile. She
peered searchingly back along the trail, glanced at the sun, and hastily
transferred to their empty canteens all but a quart from the full
canteen on the saddlehorn.

"We've got to make it last till sundown, Jack," she warned. "Then, if
only we can hold our lead, we'll be able to keep going all night."

Lennon drew out two half dollars. "How about trying these in our
mouths?"

"They'll help," she replied, and she took one. "Be ready to tie your
neckerchief over your nose, soon as we strike the alkali