"Aldrin Justice"

Barney seduces Marshall's cougar law professor to try and get him a better grade. Lily takes a job at Ted's office and tries to teach his jerk boss a lesson using her Kindergarten teacher experience.

"World's Greatest Couple"

Marshall tries to get used to being single. Barney's one night stand won't go away and Barney tries to use Lily to get out of his situation. Lily finds a place to stay.

"Ted Mosby: Architect"

After Ted and Robin's big fight, Barney tries to convince Ted that being an architecht is a great pick up line. Lily and Robin try to follow Ted's trail and discovered Ted Mosby: Architech left with a girl named Anna.

Ted's parents come to visit New York and Ted learns of their divorce they've been hiding. Robin worries that Ted's parents won't like her. Lily and Marshall try to be friends. It all happens at brunch.

"The Scorpion and the Toad"

Lily returns from her art school in San Francisco and claims she has the summer of her life, while in reality, she was miserable the whole time.

"Where Were We?"

The gang tries to help Marshall get over Lily, especially when he checks her credit card receipts and finds she's staying in a hotel nearby in New York!

To try and keep Robin from going on a camping trip with co-worker Sandy Rivers, Ted tries to make it rain with a rain dance. Lily gets accepted to her internship and California and her and Marshall break up.

The matchmaker from a previous episode finally has a match for Ted, but he thinks Robin is still the one. Lily has a secret interview for an art school fellowship in California. Barney has a war with an office worker from across the street.

"Best Prom Ever"

Lily and Robin go to a high school prom in order to listen to the band that they want to play Lily's wedding.

"Mary the Paralegal"

When Ted's jealous of Robin's date for an awards banquet, Barney sets him up with an escort.