"Keiko..." Hearing everyone's questions, the old doctor wiped his face, his expression complicated. "She was someone I caused to die."
"You've all heard the story of the 'Plank of Carneades,' right? A crew member was shipwrecked. After struggling desperately, he luckily managed to cling to a plank. But just then, another person swam over, struggling.
"That person also wanted to grab the same plank, but the crew member holding it knew full well that it could not support two people's weight. If he let the newcomer hold onto it too, they would both sink. So he pushed away the other person who wanted to cling to the plank.
"Later, he survived thanks to that floating board, while the person he pushed away drowned in the sea.
"Later still, the survivor was taken to court over it. But after fierce discussion and debate, he was ultimately not held criminally responsible."
Suzuki Sonoko understood. "I know this! This is emergency necessity under modern criminal law. Even now, something similar wouldn't result in a conviction... Hm? Wait, you were in a shipwreck too. When you said 'killing someone,' did you mean you also pushed someone away in the sea?"
The old doctor nodded wearily. "It happened three years ago, when the Toyo Maru sank. Calling that scene hell on earth would not have been an exaggeration. Briny seawater flooded into the Cabin, sweeping people off the deck. People were falling into the water everywhere. Some sank, some struggled onto Lifeboats, and others—whether lucky or unfortunate—floated on the surface, struggling.
"I was fairly lucky. I wasn't trapped in the Cabin, and as soon as I swam to the surface, I spotted a Lifeboat nearby. I climbed aboard safely, then pulled up several others one after another. Soon, that small boat was packed with people.