Irish exchange student Rory Flanagan arrives at McKinley High. He is living at Brittany's house, and she thinks he's a leprechaun. Mercedes starts recruiting for Shelby's new glee club, and Sue's run for congress picks up steam.

In honor of Valentine's Day, Will challenges the New Directions to find and perform the world's greatest love songs. Meanwhile, Rachel's two dads Hiram and LeRoy Berry pay a visit to McKinley High.

The glee club travels to Chicago, Illinois, to compete in Nationals against the best show choirs in the country, including Vocal Adrenaline, for celebrity judges including Lindsay Lohan and Perez Hilton.