Downton Abbey newcomer Daisy Lewis has been lined up for one of the biggest storylines of the fourth series, after she strikes up a relatiionship with widower Tom Branson.
The actress has joined the cast of the ITV show as the live-in nanny to Tom's daughter Sybil - named after her mother Lady Sybil Branson, who viewers saw die in childbirth last series.
And romantic sparks are set to fly between her and the former chauffer, played by Allen Leech.
"Daisy will become one of Downton's most prominent characters," a source told the Mirror. "She wowed producers in her audition and they are delighted to have secured such a brilliant young actress.
“Her romance with Tom will be one of the main storylines of the series. He will begin to develop feelings for her and they start a secret affair.
The insider added: "Tom will have an even bigger role in the new series after becoming the estate manager of Downton.
"The writers know he is a very popular character and the viewers were gripped by Lady Sybil’s traumatic death."
Daisy, 35 - whose other appearances include Doctor Who and the 2011 film Pusher, alongside model Agyness Deyn - will be one of a number of new faces on the show when it returns in the autumn.
Other newcomers will include Hollywood actor Paul Giamatti, who will play Lady Cora's wayward brother Harold, former EastEnders star Nigel Harman as a visiting valet and opera singer Dame Kiri te Kanawa as a 'house guest' at Downton.
Actor Gary Carr has also joined as the show's first major black character, a jazz singer called Jack Ross.
