The red string of fate.

Everyone has one that only they can see. Who is it attached to on the other end? No one knows until they're fated to meet them.

Sebastian, on the other hand, doesn't have one. He cut his when he was young due to his depression and hard home life.

Sebastian sighs softly as he walks down the hall. He raises his hand to gaze at the severed red string on his pinky finger. He wasn't paying attention to where he was walking, and he crashed into someone, falling on his bottom