They wake up ready to go back on their route. Edward plans to reach the hill in approximately 3 days. Getting the soul of a promising youth was quite easy, as there are many promising youths, but the rest is so difficult to get that they can only go slowly from there. And that's why they need a definite plan before they set out.
Edward starts to think. For now, he should start with the easiest thing to get: the siren's lament. Even if the siren's lament takes years to get, they at least know where to go and can make a plan from it. But with the other keys, they don't even know where to start.
First, they should go to the hill and deposit the soul, then they can start to look for a way to go to the end of the world.
He knows how to get there, but it usually involves transcending dimensions and going against the rules set by the world for mortals. Now that he is in a corporeal body forcing him to abide by those very rules, he has no idea how to get there.