Guest Stars Martin Cummins as Tom Keller Alvin Sanders as Pop Tate Barbara Wallace as Rose Blossom Christopher O'Shea as Percival Pickens Martin Cummins as Mayor Keller Christopher O'Shea as Paul Prince Christopher O'Shea as FBI Agent Perry Pierce Christopher O'Shea as Sheriff Perkins Norm Lewis as Titus Tate Co Starring Sam Darkoh as Young Pop Tate Jordana Summer as Riverdale High Student 1968 Tunji Taylor-Lewis as Black Panther 1968 Tristan Cabida as Serpent 1968 Vincent Muller as Brian 1999 Kyle Mitchell as Bus Driver 1968 Uncredited Vanessa Morgan as Raphael Lili Reinhart as Raphael Cole Sprouse as Raphael K.J. Apa as Arthur "Artie" Andrews Casey Cott as Kirk Keller Mädchen Amick as Principal Cooper Vanessa Morgan as Tracy Casey Cott as FBI Agent Drew Tanner as Flynn