As news begins to spread about the bombing at the Andrew's home, Archie, Betty and Jughead begin to deal with mysterious side effects from the explosion. Elsewhere, Veronica spirals after learning that Hiram may have been involved, and Cheryl is consumed with guilt when she believes she may have had a hand in the explosion.

After suspecting that Percival is about to make a big play, Archie, Betty and Jughead warn their friends about his potential threat to the town. Meanwhile, Toni also finds herself a target after Percival announces his plans to rid the town of gangs, including the Serpents. Finally, Cheryl makes her move against Archie, Betty and Jughead.

When several of their own fall prey to Percival's latest plan, Cheryl calls upon fellow witch Sabrina Spellman for help. Elsewhere, Percival gives Reggie an ultimatum.

When Archie and Veronica's attempt to negotiate with Percival doesn't go as planned, the forces of good and evil finally face off, leading to some unexpected revelations.

Fearing that Betty is going down the wrong path, Alice forces her to join the after-school dance show, "American Grandstand." Meanwhile, Kevin is forced by Tom to join the Riverdale High basketball team, and Veronica finds herself cut off by her parents.

Veronica sets up a screening at the Babylonium after Julian gets his hands on a stag film and invites Archie, Reggie and the guys over for a watch party. Betty unexpectedly reunites with Polly and learns about her sister's new life in New York. Elsewhere, Jughead goes to war with Dr. Werthers over his censure of comic books.

Betty enlists help from Cheryl and Toni after deciding she's going to publish her own book. Veronica, Kevin and Clay host Hollywood movie star Josie McCoy, who is in town to screen her latest film. Finally, Archie's attempt to take his poetry to the next level doesn't go as planned.