Project Hail Mary Summary & ending explained

"What's two plus two?"

The voice is flat and patient, a computer's voice. I try to answer and nothing comes out. There's a tube down my throat.

I can't open my eyes properly. I can't move much. Something cool slides into my arm and I'm gone again.

The next time, the question comes back, and this time I croak out a "four." The voice sounds pleased, in the way a machine is pleased. It asks for my name.

I don't know.

That's the first thing I notice: not the ache in every muscle, not the robot arms folding back into the ceiling above my bed. It's the hole where my name should be. I know two plus two. I know that the blood in my arm is red because of iron. I don't know who I am.

Over the next hours I crawl back into my own body. I'm in a small white room with three beds. I'm in one. The other two are occupied by what used to be people: a man and a woman, long dead, dried out and quiet.

I stand up, fall over, and stand up again.

There's a lot I can't do yet, but I can do science. So I find something to drop and something to count time with, and I measure how fast things fall in here. I run the numbers twice.

They're wrong. Not wildly, but clearly. This isn't Earth gravity.

I'm not on Earth.

I sit on the floor and breathe. A lab, maybe. A prison. A test. Every explanation leaves the same question: why would anyone put me here, beside two dead people, with a computer that checks whether I can still add?

A ladder leads up through a hatch in the ceiling. Above it is a lab, with equipment I seem to know how to use. Above that is a control room.

On the way up, a name rises out of the dark, like a bubble coming up through mud. Ryland. My name is Ryland Grace. I wish it came with instructions.

Screens wake up as I pass my hand over them. One of them shows a star.

I know the Sun the way you know your mother's face. This isn't it.