The light changed on a Tuesday.

I was in the engineering bay, welding a cracked coolant line on the port-side thermal regulator, when I noticed it. The welding torch threw off blue sparks, but in my vision—the sparks were green. Not reflected green. Inherently green. As if the blue light had been filtered through something I couldn't see.

I blinked. The sparks went back to blue.

I thought it was fatigue. I'd been on a twelve-hour shift, and the Farwalker's engine had been acting up for weeks. Sleep deprivation does strange things to perception. I'd read the reports.

But the next day, the sparks were green again. And the day after that. And the day after that.

By the end of the week, I knew it wasn't fatigue. The whole ship was green.

Not literally—the walls were still grey steel, the pipes were still rust-brown, the warning lights were still red. But in my eyes, everything had a green overlay. A luminous green haze that made the ordinary extraordinary and the extraordinary ordinary. Red became emerald. Blue became jade. White became a green so bright it hurt.

"Samira?"

I looked up. Navigator Ren Hart stood in the doorway, her arms crossed, her face set in that expression I'd come to recognize as Ren's version of worry. Ren was thirty, sharp-minded, and the best navigator the Farwalker had ever produced. She and her husband, Marcus, had been charting our course to Centauri for six years.

"Hey, Ren. What's up?"

"Can I talk to you? Privately?"

We went to the mess hall. The fluorescent lights made everything look green, and I realized with a jolt that Ren's brown hair looked copper-green under the lights. She sat down opposite me and didn't sit back. Ren didn't waste energy on comfort.

"It's about Marcus."

I felt my stomach tighten. "What about him?"

"He's been acting strange. Since we entered the nebula region three days ago. He sits in the navigation dome for hours, staring at the stars, and he smiles. Not a happy smile. A—recognition smile. Like he's seeing someone he knows."

"Marcus sees a lot of things."

"He told me something before he disappeared. Something about light."

I put down my cup of coffee. "What did he say?"

"He said: 'There's something in the light that's looking back at me.'"

Ren's eyes were steady. But I saw the tremor in her hands. Ren Hart didn't tremble.

"Where is he now?"

"Officially, he's in his quarters. Unofficially, I haven't seen him in two days. His bio-monitor shows he's alive. But the readings are—off. His brain activity is normal, but his heart rate is almost zero. He's breathing, but barely. He's like a hibernation animal."