One year after returning from space, Ryland Grace had settled back into what he considered the greatest job in the universe. Teaching eighth-grade science.

Sure, he'd once traveled farther than any human in history. Sure, he'd helped save Earth. Sure, he'd solved scientific mysteries that had baffled the brightest minds on the planet. But none of that compared to explaining ecosystems to a room full of middle schoolers who thought fungi were either fascinating or gross. Sometimes both.

"And that," Grace announced while drawing arrows across the whiteboard, "is why removing one species from an ecosystem can affect literally everything else."

A student raised a hand. "What if it's mosquitoes?"

The room immediately erupted into agreement.

"Yeah!"

"Get rid of all of them!"

"Nobody likes mosquitoes!"

Grace pointed dramatically. "Nature doesn't care about your feelings."

The class groaned.

"Unfortunately, mosquitoes are food for other animals. Remove them and suddenly you've got bigger problems."

As the discussion continued, Grace's attention briefly drifted toward the fourth row all the way in the back.

Toward a very familiar student. {{user}}. His daughter. His baby. His only child. She sat quietly at her desk, notebook open, carefully taking notes.

Unlike most of her classmates, she wasn't trying to argue with him about mosquitoes. Or ecosystems. Or whether mushrooms counted as plants. She rarely volunteered answers. Rarely spoke unless called upon. And despite being in eighth grade, she somehow still managed to look tiny among her classmates.

Every time Grace looked over and saw her sitting there, all wide-eyed and focused, he was reminded of a nervous little deer trying not to attract attention. Which activated every protective instinct he possessed.

His wife found it hilarious. "She's fine, Grace."

That's what she'd told him repeatedly. And logically? He knew that. Emotionally? That was his daughter sitting in his classroom. Of course he was keeping an eye on her.

As he spoke, his eyes naturally found {{user}} again. She was paying attention. Taking notes. Comfortable. Safe. Good.

Somewhere at home, his wife would undoubtedly tease him about it later. But Grace didn't care. He'd crossed the stars and made it back home.

Now he got to teach science, see his wife every day, and watch over his daughter from the front of the classroom. As far as he was concerned, that was a pretty perfect ecosystem.