The desert had a way of making a man believe that silence was a living thing.

Caleb Mercer had learned that during the years he spent riding patrols across the Arizona Territory. The silence between one ridge and another could be more frightening than the crack of a rifle. It could hide raiders, fever, a dying horse, a lost child, or simply the terrible realization that the next mile contained nothing but heat and stone.

On the fourteenth day of his search, Caleb's mouth was so dry that his tongue felt like leather.

His horse, a tired sorrel gelding named Bishop, stumbled beneath him.

Caleb pulled the reins.

"Easy."

Bishop stopped.

The animal's ribs showed beneath its dusty coat. The man's own canteen was nearly empty. Caleb had poured the last mouthful onto Bishop's tongue half an hour earlier.

His cattle were gone.

Forty-three head.

Every one of them carried the Mercer brand.

They had disappeared from the western pasture two weeks earlier, and Caleb had spent nearly every daylight hour following fragments of tracks across country where tracks disappeared almost as quickly as they were made.

At first, he believed the cattle had simply broken through a fence.

Then he found boot prints.

Men had driven them.

Whoever had taken his herd had known exactly what they were doing.

Caleb had followed the trail south, then west, then into a region of red cliffs where the maps became unreliable and the old military roads vanished beneath sand.

He should have turned back.

Instead, he kept going.

A gust of wind crossed the canyon.

Caleb looked toward the cliffs.

Something was different.

Not visible.

Audible.

He heard it again.

A faint murmur beneath the wind.

He dismounted.

Bishop lowered his head.

Caleb tied the reins to a scrub tree and walked toward a patch of dark earth between two slabs of limestone.

He crouched.

There.

A small depression.

The sand was damp.

Caleb brushed it away with his fingers.

Cold water seeped upward.

He stared.

For several seconds, he simply watched.

Then he laughed.

Not because anything was funny.

Because he had almost forgotten what hope felt like.

He dug with both hands.

The shallow depression became a muddy pool.

Clear water collected between the stones.

A spring.

Hidden under the desert.

Caleb removed his hat and stared at the water.

"God Almighty."

Bishop gave a weak snort behind him.

Caleb cupped his hands.

Before he could drink, a voice came from above.

"Do not."

Caleb froze.

He slowly looked up.

Four figures stood on the ridge.

Apache warriors.

Their weapons were already in their hands.

Caleb's fingers moved instinctively toward the revolver at his hip.

Then he stopped.

He looked at the spring.

Then at the men.

Something about their posture was wrong.

They weren't preparing to attack.

They were watching the water.

One of them climbed down.

He was tall and lean, perhaps forty years old, with gray beginning to touch his black hair.