While Marshall begins his summer forlorn over his break-up with Lily, Ted and Robin couldn't be happier with their budding romance.
Lily returns from San Francisco claiming that she had the summer of her life, but her friends soon see through the veneer.
When Ted's parents come to New York for a visit, their weekend ends up being far from the ordinary when a colossal family secret is unveiled.
When Barney tries to prove to Ted that his job as an architect is anything but boring by showing him that it is a great way to pick up women, a jealous Robin tracks down her man after hearing of his antics.
When Lily moves in with Barney, the trials and tribulations of their relationship may prove too much for Barney to handle.
While Barney makes it his job to satisfy Marshall's disgruntled law professor, Lily goes to work for Ted's architecture company and tries to teach Ted's big boss a big lesson.
When Marshall goes on his first real date post-Lily, Ted and Barney try to convince him the girl is crazy.
It's no day at the beach for Lily and Marshall when complications alter their Atlantic City wedding plans.
Barney uncovers Robin's secret past and the real reason behind her strong aversion to malls.
While Barney struggles with the fact that all of his friends have settled into the boring state of "coupledom," his number one wingman, his gay, black brother James, arrives on the scene.
Nobody likes a "grinch," so the Christmas-stealing Lily must be stopped after she threatens to ruin the gang's plans of a joyous holiday together due to a brawl with Ted.
When Robin tries to talk her younger sister out of losing her virginity, Barney recalls his "dirty" first time as the gang shares stories with each other about their first experiences.
Marshall is tormented by his pals after they discover a nude painting of him by Lily, but then in a twist of fate she and Marshall figure out a way to capitalize on her painting expertise.
When a funeral prevents the gang from watching the Super Bowl live, the group makes a pact not to find out who won before watching the game together the following night.
When Ted picks up a "lucky" penny, a maelstrom of bad luck ensues, but picking up the penny may be the best thing that Ted has ever done.
After taking heat from Robin for holding on to all of his stuff from ex-girlfriends, Ted gives in and parts ways with all of the items -- only to discover something that puts Robin in the dog house.
When Marshall's beloved Fiero gives out just shy of 200,000 miles, the gang recalls all of their great memories in the car.
As Ted and Robin reach a new milestone in their relationship, Barney does everything in his power to hijack their happiness.
After Barney ruins Marshall's bachelor party plans, Lily reveals a shocking secret about Barney that causes Marshall to rethink who his best man should be.
Barney is ecstatic about his appearance on the "The Price Is Right" because he has wanted to meet Bob Barker his entire life.
By the time their wedding day arrives, nothing seems to be the way Marshall and Lily had envisioned, but surprisingly Barney jumps in to try to save their special day.
When Barney overhears that Ted and Robin have a secret at the wedding reception, he begins to speculate about what it might be, but what they are hiding even stuns the unflappable Barney.
