Charlie heard Sarah shout for her to wait but she ignored her. She needed to get out of the house and clear her head, or at least think about what she was going to do. Slamming the front door harder than she meant to, she speed-walked down the street and turned the first corner. Walking as fast as she could, crossing roads, turning corners, Charlie looked for a large open space where she could sit and think for a while.

Since her teenage years, Charlie had used open spaces to help work through her problems. She would spend hours at the beach, watching the ocean waves roll over the pebbles,...