“I understand,” he said.

I hoped he did.

Then I went home to prepare for a weekend visit from two young men who still left their shoes in the hallway.

<strong>PART 25</strong>

Years later, I attended a university ceremony where Nathan received an award for community science outreach.

He had helped design an inexpensive water-testing program for rural schools, an idea that began with the little sensor he built in our kitchen.

Zachary was there, taller and quieter, working toward a graduate degree in mathematics.