[Sagi is silent. The impassive mask makes him feel a shade worse, even though he's barely seen Hien without it except as a dog. Great work, he weirded out another person to the point that they're not surprised when he does.]

Sagi...

[It's hard to tell which of his voices that is right away, but Sagi is not in the habit of calling himself by name. He doesn't look up, for once.]

Just tell him.

...I know. It's weirder if we don't.

[Saying he's fine now would obviously be false. Simply staying quiet - on second thoughts, no. Sure, he'd like to spare Hien the details. Hien is nice. But he'd also like to stop going off on people for things that aren't possible to change, things that aren't even secrets. Revisiting those memories on the film reel, remembering how much easier it was to suppress his temper when he had someone to lean on... doesn't reflect well on him lately, huh?

He takes a deep breath. When he calms down, his tone of voice is detached again.]

Marno and I... weren't supposed to be together. We were made in a lab.

[He has no reason to think Hien has heard that before, but Hien might recall Hythlo offhandedly saying something about Sagi getting "butchered at birth" before one of his nervous breakdowns and fill in the gaps.]

Everyone else in that project, it just killed them. Some fast, most slow. Some only kids, at the time.

[His distaste creeps back into his voice momentarily. He moves on anyway, spreading a hand to cap off the boring explanation.]

So when you said things like that go wrong more often than not, I just saw their faces. I'm sorry for flipping out.

[None of this actually answers the first question Hien asked. It's fine.]