SPOILERS for the answer too
Wow, thank you!! It means a lot you responded and so quickly. I forgot they could die at all, my first train was leaving them with the sunken spirit already there. This answer makes much more sense and helps a lot. I only did one scene with the knife so that's also the right place to start when I replay today. I'm excited to have another excuse to go through and really, really pay attention to the dialogue foreshadowing and hints. <3