Frances Flanagan

Simon's mother asks Alec to help stop a suicide contagion when a third student death strikes the campus. Alec ask Marisa to help when he thinks there might be more to the case. Phoebe struggles with her next career move. Rizwan learns about Simon's past.

When Margaret is disappointed that no one but Todd can attend her family Thanksgiving dinner, Todd tries to convince his brother, Lawrence, to come home. Margaret's family helps her crack a case involving an injured bank teller and robbery.

When they pose as high school students, Kati reveals she is a drop out, while Garrett's black sheep brother comes for a visit.

Panic ensues after Archie (KJ Apa) and the gang learn that Mrs. Thornton (guest star Frances Flanagan) is accused of being a communist. Cheryl’s (Madelaine Petsch) father Clifford (guest star Barclay Hope) forces her to out gay students at Riverdale High or risk losing power over the Vixens. Meanwhile, Hiram’s (guest star Mark Consuelos) surprise arrival to town is quickly met with suspicion by Veronica (Camila Mendes), and Jughead (Cole Sprouse) devises a plan to get around a boycott of comic books. Lili Reinhart, Casey Cott and Vanessa Morgan also star.