The secret tunnel

"What's worse than flying through the air and landing so hard that you can't breathe? Spending the summer with your used-to-be best friend now turned enemy fighting for your life against an old and dangerous nun who makes children disappear. But that is Sam's fate. She and her ex-friend, Calvin, must accept it if they are to survive being left in a dark mysterious tunnel with only a glowing key and an old tattered book. Their adventures take them to places they never dreamed of, and the lessons they learn might just save their lives"--Back cover. "... the perfect blend of historical fantasy and religous history"--Amazon.com.