The Fragile Threads of Power. V.E. Schwab

The first part of the series "Threads of Power"

Seven years have passed since the doors between the worlds were sealed. Seven years since Kell, Lila and Holland faced Osaron in a desperate battle to save the worlds of Red, Gray and White London.

Now Red London is ruled by Rai Maresh with his new family - Queen Nadia, their daughter Ren and consort Alucard. But his city is seething with conspiracies and rebellions, fueled by rumors that the king is forcing magic to disappear.

In White London, a new queen sits on the throne, leading her people through new rituals of sacrifice and blood, calling upon a great power that she may not be able to contain.

Meanwhile, Lila and Kell, living freely on the waves, are tasked by the captain of a floating market - to return an extremely powerful artifact stolen by unknown people.

And Tess, a girl with a knack for fixing broken things, finds herself drawn into the affairs of Antari and kings, traitors, and thieves. And only her unique abilities can change the fate of entire worlds.