One of my favourite films is The Invention of Lying, starring Ricky Gervais. This is set in a parallel world where people can only tell the truth, so there’s no acting, no diplomacy and no religion. However, the main character unknowingly develops the ability to tell a lie. As a result, everyone else believes everything he says, no matter how outlandish.
It’s largely the opposite of Jim Carrey’s role in Liar, Liar, who develops the inability to tell a lie for 24 hours, making it difficult to continue his job as lawyer.
In both cases, there is a unique element about one person in the narrative universe that conflicts with the secondary characters who can’t understand what’s going on.
However, the concept needs to be done carefully so the audience can keep track of what’s going on. In The Invention of Lying, the rules of the world are explained as a voiceover at the very beginning. In Liar, Liar, the character is shown holding a blue pen while unsuccessfully trying to say it’s a different colour.
This type of secret superpower is one I’ve explored in my own novel-writing. Here, my main character can compel others to say something or to make a simple movement. He’s not the only one with the ability, but he belongs to a select band of people who do, still allowing that conflict with the rest of the world.