Fans are about to see Ross Poldark (Aidan Turner) for the last time as television writer Debbie Horsfield confirmed Poldark Season 5 would be the show's final bow. Although BBC remains mum about the series' details, there are theories which book it will be based on and how Ross' story will continue.

"As far as we're concerned it's going to be the last," Horsfield said about Poldark Season 5, via Radio Times. The previous season was based on Winston Graham's six Poldark book, titled The Four Swans and the entire book seven, The Angry Tide, which took fans from 1780 to 1799. 

However, it is not yet revealed what path Horsefield would next take, but given that she seemed following Graham's book series, Poldark Season 5 might be based on the eighth novel, The Stranger from the Sea. The new season might begin in 1810, featuring a 10-year time jump from the last season's events. So, fans might see a 50-year-old Ross this time.

BBC also yet to reveal the returning cast members in Poldark Season 5, but there are strong assumptions original characters would make a comeback to reprise their roles. Aside from Turner, Eleanor Tomlinson is also expected to return to play as Demelza. Her appearance might be quite altered to make her look older.

Meanwhile, talking about Poldark Season 5 release date, its production company, Mammoth Screen, earlier tweeted its team was still editing the new season episodes. Hence, it may still take a little while before the show hits the small screens. 

According to CarterMatt, BBC is in no rush to announce anything about Poldark Season 5. The new season might still be months or weeks away from its release, but it would surely be out earlier than expected.

The publication noted the earliest date Poldark Season 5 could come out is on June 9. That is less than a month from today. The BFI in the United Kingdom reportedly would hold a special screening for the new season's premiere episode on June 5.

As the show's schedule alternates between June and September every year, Poldark Season 5 might be out next month. The new season's release might not be far from BFI's special screening. However, fans should only take these assumptions with a grain of salt, as the network has yet to confirm any theories or even announce its official release date.