Key Ideas & Details

1Most animals would not last a week in the Sonoran Desert without a drink. The kangaroo rat, a small hopping rodent, may go its entire life without one. Its secret is not a hidden spring but a set of habits and body features that save nearly every drop.

2First, the kangaroo rat eats mostly dry seeds. As its body breaks down the seeds for energy, chemical reactions release water, and this “metabolic water” supplies most of what the animal needs. Second, its kidneys are remarkably efficient, producing urine far more concentrated than a human’s, so very little water is lost as waste.

3Behavior matters as much as biology. During the scorching day, the kangaroo rat stays in a sealed burrow where the air is cooler and more humid. It forages at night, after the desert has cooled. Even its breathing helps: its long nasal passages cool the air it breathes out, so some of the moisture condenses inside its nose instead of escaping.

4None of these features alone would be enough. Together, they allow an animal to thrive in a place where water seems to be the one thing it cannot find.

1The bell over the door of Castillo Watch Repair had not rung all morning, and Lena was beginning to think it never would. She had agreed to mind the shop while her grandfather went to the doctor, and he had left her with one instruction: “If someone brings in a watch, write down the name and tell them Thursday.”

2For two hours she sorted springs into a tray of tiny compartments and listened to the ticking of forty clocks that did not agree about the time. Her grandfather claimed he could tell which clock was fast just by listening. Lena had always assumed he was joking.

3At eleven-fifteen, the bell finally rang. A man in a gray raincoat set a pocket watch on the counter as if it might break further just from being touched. “It belonged to my father,” he said. “It stopped the day of his funeral. I know that’s only a coincidence.” He did not sound as if he knew that at all.

4Lena reached for the order pad, then stopped. She had watched her grandfather open hundreds of watches. She knew where the tiny screwdriver lived and how to lift the back of a case without scratching it. Inside, she saw at once what was wrong: a spring as thin as a hair had slipped off its post.

5She could have written “Thursday.” Instead, she held her breath, eased the spring back into place with the tip of a needle, and closed the case. The watch began to tick.

6The man stared at it for a long moment. “Your grandfather taught you well,” he said.

7When her grandfather returned that afternoon, Lena told him everything, expecting a lecture. He only listened to the clocks for a while and then said, “The one by the window is two minutes fast. Fix that, too.”