A stranger bares their soul to you (or your character) about the greatest turning point in their life - their dark night of the soul. Something happens and you are unable to extricate yourself from this person or the situation.
Where does this occur? On a Tinder date? In an elevator? At the playground? At Burning Man? What were the circumstances surrounding this turning point? What happens to cause you (or your character or speaker) to become linked to this person?