Ted, Marshall, Lily, and Barney crash a party at a swanky New York apartment.
As Angel aids a nerdy billionaire out to retrieve some compromising photos, he encounters a group of young street kids defending their territory against invasion from a nest of vampires.
Everyone helps Joy's son plan the rehearsal dinner for his wedding; a guest from Joy's past shows up.
Leslie and Andy fight the flu as they book performers for Pawnee's Unity Concert; Tom searches for a sommelier for his restaurant; Ben looks to Ron for advice.
The firm defends a priest whose church has unusual practices; a judge orders Bobby and Jimmy to defend a man whose crime appals them.