Nicole Kidman loves challenges but this may be the toughest one yet. The 41-year-old actress will star in “The Danish Girl,” in which she is due to play the husband and eventually the wife of Charlize Theron’s character.

Nicole Kidman will also serve as a producer for the movie, which will be based on the shocking true story of a couple of Danish artists, Einar and Greta Wegener. The lives of the two took a dramatic turn after Greta asked her husband to take the place of a female model she had to paint.

Although their works of art benefited from great success in the 1920s, their happiness failed to last when Einar decided to undergo a surgical transformation. His wife may have only asked him to take on the female guise, but the little game turned out to be more serious than anyone could have imagined.

Thus, Einar Wegener came out as a transsexual woman, underwent the first sex operation in 1931, and subsequently adopted the name Lili Elbe. The change played a significant part in the couple’s marriage, which was declared null and void by the king of Denmark shortly after the surgery took place.

Anand Tucker, who helmed “Shopgirl,” is said to direct the film, which will be adapted by writer Lucinda Coxon from David Ebershoff’s 2000 eponymous bestseller, which tells the story of the Wegeners.

While Charlize Theron won an Academy Award in the Best Actress category for her lesbian role in 2003’s “Monster,” Nicole Kidman was honored with the same prize for playing Virginia Woolf in 2002’s “The Hours.”