Miss Hoover reveals she has Lyme disease and leaves the class.

Bart uses a camcorder to disrupt the class while waiting for a substitute.

Mr. Bergstrom introduces himself with a cowboy costume and engages the class.

Mr. Bergstrom starts class president nominations and Martin gives a speech.

Mr. Bergstrom leads the class in a historically inaccurate cowboy song.

Bart is nominated for class president and gives a silly speech.

Mr. Bergstrom encourages students to show their talents, including Lisa on saxophone.

Mrs. Krabappel attempts to seduce Mr. Bergstrom but he rejects her.

Lisa tells Marge how much she admires Mr. Bergstrom, but Marge defends Homer.

Mr. Bergstrom gives a creative homework assignment about rocks.

Bart's campaign for class president gets a boost from Homer.

Mr. Bergstrom tells Lisa that her intelligence will take her places.

Marge tells Homer he must take Lisa to the museum to bond with her.

Homer tries to avoid paying the suggested donation at the museum.

Mr. Bergstrom meets Homer and Lisa at the museum and gives Homer advice.

Lisa and Marge plan to invite Mr. Bergstrom to dinner.

Miss Hoover returns, revealing her Lyme disease was psychosomatic.

Bart loses the class president election to Martin.

Lisa finds out Mr. Bergstrom has left town by train.

Lisa runs to the train station to say goodbye to Mr. Bergstrom.

Lisa lashes out at Homer, calling him a baboon after Mr. Bergstrom leaves.

Homer bonds with Lisa by fixing her dollhouse and making her laugh.

Homer comforts Bart about losing the class president election.