BBC One's period drama "Poldark" will be back for its third season. While many expect the show to shed some light on the previous installment's mysteries, writer Debbie Horsfield teased one mystery that will prevail this season.

According Horsfield, who wrote the screen adaptation of Winston Graham's historical novels of the same name, the father of Elizabeth Warleggan's (Heida Reed) child will not be made certain right away. At the BFI & Radio Times Festival in London, she told the press that Elizabeth's baby daddy may or may not be the titular character Ross Poldark (Aidan Turner).

She said, "The books are really ambiguous about it, it's never said, 'Oh, it's obviously Ross' baby'. We may wish it to be, certainly for drama, it makes it more interesting but the book is not clear at this stage. We're not saying at this stage either."

As for Ross' marriage with Demelza (Eleanor Tomlinson), the possibility of his fathering Elizabeth's child is not a topic the couple is eager to discuss about.

Furthermore, the writer went on to defend the titular character, saying that he was never the typical hero type. Ross, according to her, is not perfect. "He does crass things more frequently than he should. And he does things and says things that he easily comes to regret. But that characteristic of his makes this lead character quite loveable," she says.

"Poldark" has been renewed for a fourth season. Production for the next installment will reportedly begin sometime in the fall. Turner accidentally revealed the information during the "Poldark" panel of Radio Times Festival. The actor said that they are to resume filming for season 4 in September.

The third season of "Poldark" will only have nine episodes this season, one short of last year's installment. The upcoming season returns in June on BBC One.