The story involves her hooking up again with her ex – Colin Firth's Mark Darcy character – shortly after becoming involved with Jack, an American played by Patrick Dempsey. Then she becomes pregnant.
"I can't go back and keep on making the same mistakes when I can make new ones," she writes in her diary. Emma Thompson, portraying her OBGYN, tells her to try to figure out which man is the father – "It's like the final of The X Factor" – but each man still believes it's him by the time that they carry an about-to-deliver Bridget into the hospital.
Bridget Jones's Baby is the third instalment in the franchise, which launched in 2001 with Bridget Jones's Diary and followed in 2004 with Bridget Jones: The Edge of Reason.
Tim Bevan and Eric Fellner of Working Title Films produce alongside Debra Hayward.
Jim Broadbent and Gemma Jones return to portray Bridget's parents. Sharon Mcguire, who directed the first film, came back to direct Bridget Jones's Baby. It hits Australian cinemas September 15.
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