Season 5 of hit musical drama Glee is going to be difficult for fans and cast alike following the death of Cory Monteith and a new sneak peak trailer hinted at some of the unavoidable grief in the memorial episode.  

A brief clip of Rachel, played by Lea Michele, shows her dressed in black with a sombre expression on her face.  

A memorial episode is being planned for Monteith's character, Finn, who has had to be written out of the show.   

The episode will be called The Quarterback and E!Online is reporting that there will be appearances from returning guest stars  Amber Riley (Mercedes), Harry Shum Jr (Mike Chang), Mark Salling (Puck), Jayma Mays (Emma), Dot-Marie Jones (Coach Bieste), Mike O'Malley (Burt Hummel) and Romy Rosemont (Carole Hudson-Hummel).

It is understood that Michele won't appear in the special episode until close to the end.

The memorial episode is set to come three episodes into the new series, when news of Finn's death will be broken to the characters.

One source told Hollywoodlife.com that the memorial episode would be a "celebration of Cory's life and the difference he made to us and the fans of the show".

Michele recently tweeted a picture from the set of a 'Finn' necklace, similar to the 'Cory' necklace she wears in real life.

The promo trailer also revealed that Coach Sylvester, who was fired at the end of Season 4, will be back and this time as principal.

There is also the possibility that Blaine, played by Darren Criss, will propose to his long-term boyfriend Kurt, played by Chris Colfer.

"At the end of Season 4 there was a little cliff hanger to do with a little box behind Blaine's back," says Criss in the promo.

'Blaine is getting ideas... It might have to do with something that rhymes with suposal. '

Music from the Beatles will also be figuring big in the Fox show.

Criss hinted: "We are coming back with one of the greatest secret weapons - Beatlemania. Beatles is a big deal for me."