There would no going back once they began. A beginning that may lead nowhere, that may have opportunities to end after they started--but they wouldn't know, and there would always be a risk. That the risk they were taking wasn't worth the consequence, that the result would be as worse--or more--as Roland voiced.

Tidus stands without pause, faces Roland in acknowledgement and gives one look back out to the sea, but then turns for the train. Everything they had to get started was there: the paper, the few details they wanted. World numbers on the sheets of the mission guides, the copy of the ministry report somewhere in the library...

They could hatch out the details off-board once they got it together. But whatever came, whatever happened... at least they tried.