Our lives are written by the hand of other people. Some have entire chapters dedicated to them. And someone's presence can be contained in just a couple of lines - a random fellow traveler, a postman, a seller from a bakery - but sometimes they can influence our fate.

Helen and Sarah met on the bridge when one of them was full of desire to live, while the other dreamed of forgetting. They were separated by ten years, different upbringings and characters, but they still became friends, invisible pen pals, carefully keeping each other's innermost secrets.

But what does sincerity really mean for Helen and Sarah? And to what extent can you trust a stranger without fear that one day you will be bitterly disappointed?