Aster is a doctor with a goddess's magic. Iris is his assistant.
Or so goes the ruse that has followed the twins from poverty to the highest halls of Ventaris.
In reality, Iris evaded death by becoming Aster's tether: a channel that stops his magic from destroying him and keeps her alive. They share ambitions, pain, and emotions. Everything but equal control over that power.
When Iris is charmed by their new patient, a noblewoman tortured by nightmares, Iris's loosening grip on her identity and her envy threatens to destroy that connection, and both siblings along with it.