Dracula is on the verge of coming into his full power. Department 19 is on the back foot. Ladies and gentlemen: welcome to war. The stakes? Mankind's very survival.As the clock ticks remorselessly towards Zero Hour and the return of Dracula, the devastated remnants of Department 19 try to hold back the rising darkness.Jamie Carpenter is training new recruits, trying to prepare them for a fight that appears increasingly futile. Kate Randall is pouring her grief into trying to plug the Department's final leaks, as Matt Browning races against time to find a cure for vampirism. And on the other side of the world, Larissa Kinley has found a place she feels at home, yet where she makes a startling discovery.Uneasy truces are struck, new dangers emerge on all sides, and relationships are pushed to breaking point. And in the midst of it all, Department 19 faces a new and potentially deadly threat, born out of one of the darkest moments of its own long and bloody history.Zero Hour is coming. And the Battle Lines have been drawn.