Harriet’s ambition to know and see everything may change reclusive Agatha K. Plumber’s life for the better.

Harriet’s new coat is perfect for her—and Marion Hawthorne, apparently. But who will win the school’s vote?

Janie and Harriet vow never to go to dancing school, but Harriet doesn’t know that Janie actually likes dancing.

After an awful day, Harriet wants some alone time. Watching Mr. Withers’ 26 cats is just what she needs…or is it?

Harriet learns about her middle initial and questions who she is. Her nanny, Ole Golly, teaches Harriet a valuable lesson about identity.

Janie and Harriet get to meet their favorite singer, only to discover a shocking truth about his music.

Harriet really wants to win a photo competition, but it means teaming up with someone she doesn’t see eye to eye with: her mom.

Sport and Harriet think it’s time to get rid of their beloved stuffies, but change their minds—and the narrative—thanks to Marion’s sneaky reporting.

Harriet adds the Garcia family to her spy route…and discovers that someone is spying on her.

On her birthday, Ole Golly revisits a list of everything she wanted to do by the age of 35—and Harriet is determined to help her complete it.

When Harriet loses her last—and favorite—baby tooth, she struggles with saying goodbye to her babyhood.

The Welsch family attends a neighborhood party where Harriet is determined to find out why the Robinsons are so boring.

At the world’s fair, Harriet meets a 14-year-old photographer who’s unsure of his future—but shows Harriet how to cherish today.

Sport joins Harriet for a local scavenger hunt. But when he brings his good-luck charm to improve their chances, Harriet is skeptical.

While Harriet’s parents are out, she and Ole Golly join Mr. Waldenstein for a movie date. But can they get home before Harriet’s parents do?

When Ole Golly announces she and Mr. Waldenstein are getting married and moving to Montreal, Harriet tries to change her mind.

Harriet’s dream of creating a post–Ole Golly life is shattered when her notebook falls into the hands of her nemesis: Marion.

The fallout from her private thoughts becoming public leaves Harriet fighting to repair her friendships—and for the return of her notebook.

With the notebook causing quite a stir, Harriet hopes a backyard trial of her peers will prove her innocence.

After Harriet makes an unexpected discovery, she comes up with a plan to right her wrongs.