Alexa Daley and her father return to the walled city of Bridewell, where Mr. Daley has more strictures for Alexa’s behavior than ever. Nevertheless, Alexa leaves Bridewell through its underground tunnels led by Yipes, her tiny companion from Dark Hills Divide. Instructions in a letter from Warvold lead them in a quest to free the dead leader’s wife from imprisonment in the Dark Tower on the other side of the eponymous valley. Gutsy Alexa centers this story, always ready to foster cooperation and accept help from well-intentioned friends, be they human or animal. Animal characters take an active and effective role in the adventure. The plot takes off a lot faster than in the first installment, because Carman integrates the backstory as needed in the text, rather than allowing it to slow down the pace. Although the resolution of this tale satisfies, it ends on a cliffhanger, leaving readers to wait in suspense for the story’s finale. Still, a trip with Alexa Daley through the Valley of Thorns is well worth the effort. (Fiction. 10-12)