Barney is excited to get the gang to come with him to a grandscale fighting match called "Robots Versus Wrestlers".
Barney had bought a fifth ticket for Robin, despite knowing she had wished to spend time away from them, and indeed she ends up declining.
Ted has a great time at the party, becoming a big hit, while Marshall, Lily, and Barney find it boring and want to leave.
Ted decides to stay, leaving Barney hurt, as he, Marshall and Lily head to the Robots event.
At "Robots Versus Wrestlers", Barney is bothered by the fact that their group appears to be growing apart: Robin moving in with Don, Ted leaving them for the party, and Marshall and Lily possibly having a baby soon.
Meanwhile, Ted continues to have a good time at the party and begins reciting a poem to everyone there, in the original Italian.