I think I hit a bizarre bug.
Quick overview of my choices: flirting with Bell at the start, saved him, margaret died the first night, took Lu in. Shifted to trying to romance Lu the moment he arrives. Get the shell scene, which can lead into Lu dying and taking me to an actual ending (a not very happy one) with the affection choice.
Or, I can pick the say nothing option, wait out the timer, have the guide hurt, fight through, and then....nothing. It gets to the Guide saying "We need to start walking, we already lost enough time as it is." and bam, I'm brought to the main menu. Everything just stops there.