My Royal Lesson (Kingdom University, #4)

Kingdom University Series, Book ＃4 || Learning from this guy is not as easy as I thought it would be.

30 Doors

When a mysterious mailer sends a puzzle to Vladimir, a talented operations manager of an e-commerce company, he is doomed to answer riddles, assemble puzzles, and play a bloody game to get to the safe ground. But with his past haunting him every deadly game, can he survive the terrifying 30 doors even if it compromise...