But despite the reunion, it's not the happiest occasion as Principal Sue is sticking to her guns and, following their loss at Nationals, is forcing the show choir to disband.
Former favourites return to say goodbye and reinvent performances from days gone by. Fans from around the world have chosen the songs they'll sing, so we're sure for some old faves.
As the gang go down memory lane, it's up to April and Holly Holliday to concoct a plan to save the glee club, but will it work?
Glee, Sky1, 9pm
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