Robin's musical past emerges again as the group learns of someone named Simon from Robin's past. Barney searches for more Robin Sparkles memorabilia.

Barney's discovery of a Canadian kids show called Space Teens, that Robin appeared on as Robin Sparkles, leads the gang to get her to reach out to her co-star, Jessica Glitter.

Lily and Marshall receive shocking news that has a profound impact on the gang. Ted begins his duties as best man for an old friend's wedding.

While Barney prepares for his wedding to a mystery bride, he and Ted reminisce about Punchy’s wedding, including when Marshall and Lily announced they are having a baby. Meanwhile, Robin considers telling Barney she has feelings for him.