How will the story conclude?

So we thought that Rowan would be the last, bravest person left to face the dragon, and it has got to that point, our prediction was accurate.
BUT... How do you think Rowan will defeat the dragon and then how will this make the water start flowing again?

(All this in just one last chapter????  Isn't it great how the author builds up suspense until we just can't wait to read the ending?!!)