The little guy gets a "hi" when he appears, just to be polite--and because, hey, he's fun....if it's a he--and he doesn't know if that's a yes on the creature (thing) being useful as a source of light, but Tidus doesn't mind the company. Seems it's just around Roland all the time, whether or not it can be seen. Huh.

"Covert heist means...just between us?" There's a sheepish end to that question, a guessing that doesn't cover itself, but with Tidus figuring he should know already what exactly Roland means. This type of action isn't his forte, in the movies or real life. "We should probably keep it on the down-low for now, yeah? Some people are gonna think its risky, just like you. And it is. But...I'm willing to take that risk. We can't just sit around and hope something happens."

They're throwing more than themselves into the consequences if anything results from this, but already, each of them were at risk. The train wasn't forcing them into action, but wasn't it as close to manipulation to give them the chance at freedom at the cost of putting their lives on the line? No one was trying anything, and it'd already been going on for five or six months. How long were they going to wait, let this go on?

"But," he says as he walks, "we might need more than letter and bottles too...if we can get more. We just need to be careful about what we ask."