Actress Lara Dutta Bhupathi is all set to take the audience by surprise as she plays Indira Gandhi in the espionage drama 'Bell Bottom', which is slated for an August 19 theatrical release.Calling it an opportunity of a lifetime, she said it was a great responsibility to play the late former Prime Minister."It is a great responsibility when you portray someone who's an iconic figure like Mrs Gandhi. It was very important to get her body language right," the 46-year-old actress said at the 'Bell Bottom' trailer launch.The film, incidentally, is set in 1984, the year that saw Operation Bluestar as well as Mrs Gandhi's assassination."The film is about a hijack that took place during Mrs Gandhi's tenure," the actress said, describing the outline of the plot."Given the dramatic events that were unfolding, she was extremely centred. It was important therefore to portray her in that way. As a result, a lot of homework and research went into the role. It was an opportunity I am very thankful for."