"I'm sure." Especially since they're doing this now anyway, so Inigo then doesn't want to leave it all up to Yugi.

But after he takes the book from the other, he just ends up staring at the blank page for a moment. The ridiculousness of the situation aside, what does he even write? How does he even summarize their situation..?

After that moment of thought, he leans down, starting to write 'We're still out here.' on the paper before handing it back to Yugi.

"There, you can add to it. .. Oh, and I guess we should put our names on it too."

Just in case the train does actually somehow notice it, even though he doubts that will happen.