Why you should read the Shades of Magic series by V. E. Schwab

Imagine four Londons, all of them existing in the same space and time, known as Black, White, Red and Grey. Black London has been completely consumed by magic with nothing left behind. In White London, magic is scarce, the people are power hungry and it’s only getting worse as they’re the only thing standing between the dark consuming magic in Black London and everything else. There’s Red London, with plentiful magic and powerful magicians.