Ok, I figured out the problem and fixed it. But before I send the patch, we should figure out the text (since it's now hack-isk ascii because of space constraints). The question "Are you ready?" seems out of place. Especially since it's a whole 'nother screen (screen change) before he asks it. Nothing that happens before it, gives it any sort of context. There's no pause or in-game event preceding it that gives hint. I guess it's a forewarning of sorts, as a question. But it just seems odd. "Be on your guard" or "Be on your guard..." seems to fit fine. Although the "..." is probably way overused, it seems to fit here IMO.
As for the first string, it doesn't necessarily have to be the same as stage 4. The ferryman in stage 2' skips you to stage 3, completely avoiding the boss in stage 2'. I mean, he's actually taking you somewhere different. Unlike the one in stage 4' who only takes you across.