Seth, brother of Sara, a boy with the power to control his molecular density – "phasing" to become very dense, evidently giving him some degree of invulnerability, or become insubstantial and pass through solid objects. He is a distant person at first until he knows he can trust, protective over his family and friends. Both siblings talk using overly formal, emotionless, and analytical voices, and are always addressing people by both their first and last name in all situations.