"The Quarterback," the third episode of the series' fifth season, was dedicated to the 31-year-old actor who died in July from an alcohol and drug overdose.
The episode takes place weeks after Hudson's death but does not explain how he died or show his funeral. Instead, it focuses on how the McKinley High students reunite to celebrate their friend's life.
Lea Michele's character Rachel, Monteith's on and off screen girlfriend, appears at the end of the episode for and amazing rendition of Bob Dylan's "Make You Feel My Love."
"I loved Finn, and he loved all of you guys," she said before singing the showstopper. "I used to sing in the car and before him, I used to sing alone. This is the first song I sang with him when we would drive around together."
Glee showrunner Ryan Murphy told E! News it was "very difficult" to write the episode.
"It was done with a really pure feeling of love for [Monteith]," he said. "I think that's what that episode is about -- treasure your friendships when you have them because one day they're not going to be there. The actors and the crew had a really hard time shooting it."