Rachel and Kurt pay a visit to Lima as the glee club launches its production of "Grease." Meanwhile, Cassandra July returns to shake things up in Rachel's life, and Santana comes back to lend a helping hand.

It's time for Sectionals, and New Directions receives guidance from some of the recent McKinley graduates who volunteer to mentor the glee club during their Thanksgiving breaks. Meanwhile, Rachel and Kurt have a non-traditional holiday dinner in the Big Apple.