Riverdale Season 7 Trailer
Click to viewFor those of you who need a refresher on last season: After defeating Percival by bringing him to Rivervale and sending him back in time to before he made a deal with the devil to become immortal, Veronica absorbed everyone's super powers and gave them to Cheryl to help her defeat Bailey's Comet before it could destory Riverdale. But in doing so, the combination of all their powers broke the universe and somehow sent everyone back in time, to 1955, where only Jughead remembers their lives. Also in that episode, Betty and Archie got engaged, Jughead and Tabitha saw their entire future together and Cheryl discovered that she and Toni are literal soulmates.
But now that's all gone to shit for at least the first half of the final season, as seen in this trailer, where everything is extra weird and characters are making out with people they should not be making out with (in gay Kevin and lesbian Cheryl's cases, probably to avoid being hatecrimed).
Source.