For Samantha Miller's young fans - her 'girls' - she's everything they want to be. She's an oracle, telling them how to live their lives, how to be happy, how to find and honour their 'truth'.

And her career is booming: she's just hit three million followers, her new book Chaste has gone straight to the top of the bestseller lists and she's appearing at sell-out events.

Determined to speak her truth and bare all to her adoring fans, she's written an essay about her sexual awakening as a teenager, with her female best friend, Lisa. She's never told a soul but now she's telling the world. The essay goes viral.

But then - years since they last spoke - Lisa gets in touch to say that she doesn't remember it that way at all. Her memory of that night is far darker. It's Sam's word against Lisa's - so who gets to tell the story? Whose 'truth' is really a lie?