Ryan Murphy is not ready to reveal the theme for Season 6 of American Horror Story because he and co-creator Brad Falchuk haven't picked one yet. "We've been working on two ideas at once, which we've never done," Murphy revealed at the American Horror Story: Hotel panel at the 2016 Paley Festival. They'll reveal which idea they've landed on for next season "soon," according to Murphy.
Though rumors have pointed to a season about the Slender Man myth, Entertainment Weekly shot that report down. However, Murphy said that both potential ideas include children. In January during the winter TV previews, FX president John Landgraf teased that the new season of AHS will be "set in the present" with "echoes of the past." Murphy added at Paley that you can expect more tie-ins to previous seasons of AHS.
As for the cast, Murphy wouldn't confirm which actors would be returning, but invited back "all of the darling people" on stage -- Sarah Paulson, Kathy Bates, Denis O'Hare, Matt Bomer, Wes Bentley, Cheyenne Jackson, and Finn Wittrock -- if they were interested. Hotel stars Lady Gaga and Angela Bassett have already confirmed that they are returning in some capacity for Season 6.
Landgraf also suggested that FX and Murphy were exploring the possibility of two seasons of the show per year -- one in the fall and one in the spring, which would explain Murphy's claim that he and Falchuk had two themes in the hopper.
American Horror Story Season 6 will premiere in the fall.