Joy Malone finally knows who she is, where she comes from, and how to live in two worlds at once. And now she can introduce her family and friends to her mysterious boyfriend, Indelible Ink. But when Ink's twin sister, Invisible Inq, calls in a favor, Joy must accept a dangerous mission to find a forgotten door between worlds - a door hiding a secret that some will kill to keep.
Some things are permanent. Indelible. And they cannot be changed back. Joy Malone learns this the night she sees a stranger with all-black eyes across a crowded room - right before the mystery boy tries to cut out her eye. Instead, the wound accidentally marks her as property of Indelible Ink, and this dangerous mistake thrusts Joy into an incomprehensible world - a world of monsters at the window, glowing girls on the doorstep and a life that will never be the same.
Joy Malone has learned to live between two realities, surviving mortal threats and agonizing betrayals. And she's found true love. But the world of the Twixt is in chaos, and the Council wants someone to blame.... Facing a danger greater than any she's ever known, Joy must find the strength to rely on herself as her allies fall away, because Joy is no longer sure just who - or what - she is. She knows only that her deepest secret is also her greatest vulnerability and the key to saving them all.