The Fragile Threads of Power

Seven years after the Shades of Magic trilogy, Kell has learned to fight without magic, because using it now causes him pain, and Lila has become a ship's captain who sometimes spies for the Crown. Rhy rules Red London, and a group called the Hand is plotting against him.

A new character, Tes, who can see and shape the threads of magic, is caught up in it as well, and the four Londons, long linked by magic, are slowly fading. The first book in the Threads of Power series.