V
V.E. Schwab
Shades of Magic
A completed fantasy trilogy set across four parallel Londons — Red, Grey, White and, once, Black — each holding a different relationship to magic. Kell, one of the last Antari able to travel between them, serves Red London as an ambassador until a smuggled artefact and a Grey London thief named Delilah Bard pull him into a struggle over who controls magic itself.
The series should be read in publication order: A Darker Shade of Magic, followed by A Gathering of Shadows, and then A Conjuring of Light. While each book has a distinct arc, the overarching narrative and character development are best experienced sequentially.
Yes, there is a spin-off series called Threads of Power, which continues the story in the same universe. The first book in this new series is The Fragile Threads of Power.
The original trilogy, consisting of A Darker Shade of Magic, A Gathering of Shadows, and A Conjuring of Light, is complete. However, the story continues in a new series set in the same universe, Threads of Power.
As of my last update, there have been discussions and options for adaptations, but no film or television series has been officially produced or released.