The Girl in Sabine's Head, the Screenside Trilogy, Book--3

Sabine's lost her mind.
Esmeralda's found her body!
In Paris, Esmeralda draws the beautiful and insane Sabine as the first mental patient to be assisted by their world.
The relationship starts off uneasily, as the two girls bicker often over who should have charge of the physical body – Esmeralda, the newcomer helper and controller who makes it work, or the now helpless Sabine, who has owned it since birth!
As these two delightful girls rob ATMs for spending cash, and quarrel their way around Paris and France, that which is happening in the background turns out to be the main game, in which they are merely pawns of the evil group planning for deathlessness, and perfecting the systems of the future.
It is a terrible and violent future, in which the Human Race itself could be obliterated!