#52 Turn Coat by Jim Butcher

By the end of this book the I think Harry has been dealt some of the worst emotional blows he has has for the entire series. Most of the plot is Harry trying to save Morgan the one wizard warden that has always wanted him dead.  Morgan is accused of  treason against the wizard council. By the end of the book, Harry's pet theories about the council is proven. This is certainly a pivotal book in the series and now I have to sit and wait for the next one.

Turn Coat (The Dresden Files, #11)