Soul

Every single baby is given a stone at birth. These stones match a soul mate. There is an old belief that these stones will show you a sign when you find your soulmate. They could light up, get warm, etc.
But this story if often just referred to as a fairy tale because no one has ever seen anything out of the ordinary happen. Two people meet and fall in love the normal way. There are others who claim to have had their stones light up when they met the right person. But people still don't have any actual evidence to prove it.
There are some people who have searched their whole life to find their soulmate. And there are people who are just starting out, like Annabel Berkeley. She has just turned 18, and according to the fairy tale, her stone has been fully activated at her age. But she does not have much interest in searching for her perfect match. She'd rather keep to herself then get involved in that silly, little thing called love. But she does keep her stone close to her, just in case she ran into the right person.