"The Silence of the Louise" is the second episode in Season 8, being the one-hundred-and-thirty-first episode overall.
When Mr. Frond's therapy dolls are mysteriously attacked, Louise teams up with Millie to help solve the case. Meanwhile, Teddy decides to get into the inspirational poster business, but ends up with mixed results.
Louise is shown reading Old Yeller in an attempt to win the student body a trip to a waterpark after reading 500 books. Mr. Frond shows them that his dolls have been mutilated, and until the culprit comes forward or is caught, there is no waterpark trip. Louise accuses Millie, but Frond says that Millie is out recovering from a dental procedure.
The siblings go to Millie's house, revealing that Millie's obsession with Louise follows her home. They ask Millie for help with the case, and she agrees to in exchange for playdates, and Gene and Tina leave.
Louise and Millie investigate but are constantly interrupted by Millie's demands to hang out. They discover that one doll was cut up, and go to Edith and Harold, who say the doll was unraveled, not cut up. Zeke fesses up to Frond for the crime. As Louise and Millie end up in a telephone argument, the final doll unharmed is found to have been destroyed, Zeke's innocence is shown, and the waterpark trip is re-canceled.
Louise manages to reconcile with Millie in order to find the true culprit. After discussing Old Yeller, Millie reveals that Frond did it. As the siblings confront him, Frond runs out of his office. After he and two other teachers are cornered in the teacher's lounge, they reveal that they deliberately destroyed Frond's dolls as they spent all the waterpark money on coffee pods. They agree to not tell the principal if they bring back the waterpark trip. Louise ends up acting somewhat friendly to Millie at the waterpark.
Meanwhile, Teddy reveals he is now the business partner of Janine, the owner/operator of Yours Truly Stationery, and that they are going into the motivational poster business. Bob does not find it to be working. As Linda visits Teddy and his partner, the two partners get into a dispute but quickly reconcile. As the business fails, Bob finally finds the poster inspirational and is shown way more productive. Due to this, they go to save Teddy and Janine's business.