The Vanishing (1988)
Raymond Lemorne: You start with an idea in your head, and you take a step... then a second... Soon, you realize you're up to your neck in something intense, but that doesn't matter. You keep at it for the sheer pleasure of it. For the pure satisfaction it might bring you.
Saskia Wagter: My nightmare. I had it again last night.
Rex Hofman: That you're inside a golden egg and you can't get out, and you float all alone through space forever.
Saskia Wagter: Yes, the loneliness is unbearable.
Saskia Wagter: No. This time there was another golden egg flying through space. And if we were to collide, it'd all be over.
Raymond Lemorne: My daughter was bursting with pride. But I thought that her admiration wasn't worth anything unless I could prove myself absolutely incapable of doing anything evil. And as black cannot exist without white, I logically conceived the most horrible deed that I could envision right at that moment. But I want you to know, for me killing is not the worst thing.
Rex Hofman: Sometimes I imagine she's alive. Somewhere far away. She's very happy. And then, I have to make a choice. Either I let her go on living and never know, or I let her die and find out what happened. So... I let her die.