Excerpt:

Cassie felt oddly superstitious about opening the box. She glanced again at her door to be sure it was still shut, even knowing that she was the only one in the house – her mother would be at work for at least two more hours, and longer if the traffic was bad on New Circle. The two of them were the only ones who lived in the little house, and Cassie hadn’t had a babysitter for three years now. Maybe she should wait until her mom got home. No, this was her adventure, her secret, magical box. She put a finger to the cold metal of the latch, feeling again that tingle, like a thrill of excitement, that had convinced her to buy the box in the first place. She slid her thumbnail under the raised edge of the latch to flick it open.
The latch stayed stubbornly closed.