Season 3 sees Will Ferrell, an executive producer,
playing children's author Roald Dahl
during his
days as a British spy; Josh Hartnett as Hollywood
icon Clark Gable; Oscar winner Octavia Spencer as abolitionist Harriet Tubman; Topher Grace as board game mogul Milton Bradley; Michael Cera as the leader of the New York newsboy strike of 1899; Dennis Quaid and Sam Rockwell as mobsters Lucky Luciano and Bugsy Siegel; Jack Black as Los Angeles water system architect William Mulholland.