Homeland star Damian Lewis has insisted the hit US show could continue without him.
The show, which also stars Claire Danes, has been hailed as the best new US drama on TV.
British actor Lewis, who plays Nicholas Brody, said the creators are of the opinion that "you can't flog this as a dead horse forever...".
He told the Radio Times: "It will run its natural course. If that's only four years, it will only be four years... and there's no guarantee that my character will be around."
The Golden Globe winner added: "The series could rebirth itself each year by just finding a new threat. So you can go past Brody because the anchor of the show is in the CIA, it's in the threat to homeland security."
Lewis recently revealed that he has signed a seven-year Homeland contract, but insisted his deal did not guarantee a future on the series.
His British co-star David Harewood's character - CIA operative David Estes - was recently killed off in the drama, broadcast on Channel 4.