Complex sentence: The premise of the film is that a meteor has been projected to destroy Hong Kong after 33 years (i.e., in 2047), the subsequent reaction of local residents and the transformation Hong Kong undergoes leading up to the date of destruction.
Split into simpler sentences: The premise of the film is that a meteor has been projected to destroy Hong Kong after 33 years (i.e., in 2047). The storyline details the subsequent reaction of local residents and the transformation Hong Kong undergoes leading up to the date of destruction.