Mallory's two best friends' parents are getting married, and Mallory fears that she will become a third wheel when Mary Ann and Joey become stepbrother and stepsister.
Mallory enters fourth grade with high hopes for her best year ever, but instead she starts by breaking the teacher's rules and then feels left out when her best friend likes the same boy she does.
The Wish Pond Road gang heads to Camp Blue Lake, but once they are there, Mallory realizes it is not as much fun as she had hoped, and begins to wonder if she made a big mistake in coming.
Mallory's journal of her fourth-grade trip to Washington, D.C., reveals how much fun she has, despite a loose tooth, being upset with her best friend, Mary Ann, and getting separated from her class in a museum.
After moving, eight-year-old Mallory struggles with being new at school, especially because her mother is now the music teacher and director of the third grade play.
After moving to a new town, eight-year-old Mallory keeps throwing stones in the "Wishing Pond" but things will not go back to the way they were before, and she remains torn between old and new best friends.
Ten-year-old Mallory's crush on J.T., a boy in her older brother's class, gets her in trouble with her teacher, her family, and her friends but no matter what she does, J.T. does not seem interested in her.