Raising Sleepy Stones by P.H.T. Bennet

[Dorothy]

Like every kid in Solasenda, Kiva Stone has been far too busy training for one of the five town guilds to think about something as useless as dreaming. But when she and her sister DeeDee uncover a mysterious plot to get rid of them, their only hope lies with a shadowy group of people who wield unimaginable powers drawn from their dreams. As the girls escape with them up the Varruvyen river, they start learning secret Dreaming Way techniques that have been forbidden for centuries. But how can they learn enough to stand against the enemies chasing them? The answer lies in the shattered history of Orora Crona, the lost Valley of Dreams, and whoever can piece it together first will rule for centuries to come.