As this enchanting picture book begins, a young boy is fondly remembering last summer, when his dad built an awesome tree house in their backyard. "My brother and I spent most of that summer in the tree house. It was the best summer ever." Sadly, everything has changed this year. His brother is now "too busy with his friends" to come to the tree house at all. But then one night the power unexpectedly goes out while the young boy is there by himself,...