In the town of Cabrillo, California, there was a neighborhood called Pepper Street, where every house stood behind a bright garden and a perfect white picket fence. The families who lived there appeared to be just as neat and put-together as their picture-perfect homes. 

At the very end of Pepper Street stood a tall brick wall that separated the neighborhood from the rest of the world. In a way, it was fun — the children liked pretending that Pepper Street was their own little island, tucked safely behind the wall. But one morning, surprising news spread from house to house: the wall might be coming down. The grown-ups grew uneasy at once and thought to themselves, “What if new people come in and change our lovely street?”

Three-year-old Caroline, the youngest of the neighborhood kids, toddled between their chairs as they sewed, listening to the soft hum of gossip mixed. Every so often, one of the moms would lean in, lowering her voice as she mentioned how some of the older girls were getting too mature too fast, and how their attitudes rubbed off on the other children. That's what started all the letters they wrote.

The men in the neighborhood would play golf on the weekends, while their children played in the creek. Two of the neighborhood boys played in the creek and repeated the words of their fathers, who would talk down on the neighbors that weren't members of the club. Not only is there a separation from those in the neighborhood and the rest of the world, but there are also levels within the neighborhood.

One afternoon, while the other neighborhood kids played outside, Tod Donald slipped quietly into the Desmond house, where little Caroline and her older brother Johnny lived. He wandered from room to room as if exploring a secret world, poking through Mrs. Desmond’s dress closet and examining Caroline’s room.

Mr. and Mrs. Roberts had two boys, Art and Jamie. One afternoon, Mrs. Roberts announced that she had hired a housekeeper to help around the house. Her name was Hester and she was around the same age as Artie. From the start, Mrs. Roberts wasn’t very kind to Hester, and the neighborhood kids weren’t either. They treated her differently simply because she lived on the other side of the wall.

Another neighborhood girl, Marilyn Perlman, created an unexpected friendship with Harriet Merriam. Both girls were often teased by the other kids; Marilyn because her family practiced different traditions, and Harriet because she looked a little different.

Down by the quiet creek, the two girls found a place where none of that mattered. They read books side by side, shared their secret stories, and wrote letters to their future selves, promising they would stay best friends forever.

The grown-ups on Pepper Street liked rules. Some rules were for safety, and some rules were for keeping everything “perfect.” Sometimes the rules were kind, and sometimes they were unkind — especially when adults decided who should be allowed to play together and who should be left out. Marilyn and Harriet’s friendship ended because of grown-up rules. Both girls were upset and were back to feeling alone.