https://www.etonline.com/riverdale-showrunner-roberto-aguirre-sacasa-reveals-this-weeks-episode-will-be-luke-perrys-last

"This week’s #Riverdale is the last episode Luke filmed," creator Roberto Aguirre-Sacasa tweeted last night. "As always, Fred’s imparting words of wisdom to Archie. A beautiful, true moment between a father and his son. Wish these scenes could go on forever..." Perry died on March 4 after suffering a stroke on Feb. 27.

I've never seen that show but I want to watch it from the beginning.

Luke Perry's last Riverdale scene was sweet, short and poignant -- a reminder of why he'll be missed (https://decider.com/2019/04/24/riverdale-luke-perry-final-scene-chapter-fifty-four-fear-the-reaper/)

Riverdale fans shed tears (https://www.syfy.com/syfywire/luke-perry-riverdale-finale-episode-twitter-reactions) on Twitter over the last scene (https://www.youtube.com/watch?v=Xp7iQdaOIUU) featuring Perry as Fred Andrews, filmed before he died last month from complications of a stroke at age 52. Perry's final appearance was appropriately in support of K.J. Apa's Archie, and came about four minutes into Wednesday's episode. "Nobody could have predicted this would be the last time we would see the Andrews family patriarch, so it isn’t a proper goodbye; but it is a sweet, short and poignant reminder about what Perry brought to the show," says Alex Zalben. He adds: "The roughest part about watching this scene is that it’s clear there was something more planned there, and Fred was an important part of at least one of the season’s ongoing mysteries. As is, it looks like Molly Ringwald, who plays Fred’s separated wife Mary Andrews, will be joining the last few episodes to take the place Fred would have in the plot. That last glance though, that thought, whatever it was, will never be continued." ALSO: Perry's final appearance is a reminder of what Riverdale loses without him (https://www.hollywoodreporter.com/live-feed/luke-perrys-final-riverdale-episode-explained-1204363).