If nothing else, the way the other passengers leave the train is obviously a source of discomfort, and Tidus doesn't need to confirm verbally; Phineas doesn't pry, just files that away and lets it pass.

To play heroes is a surprise as well, obviously, and Phineas tries to figure that out as Tidus explains. "Not really. Not that I know of. I'm an inventor, actually. I know a lot more about technology, and with sufficiently advanced technology, 'magic' can be faked... But you're saying that this was actual magic?"

Just wanting to confirm that. Also, "And that we're being press-ganged into emergency services?"