Mace Windu returns to his homeworld, Haruun Kal, in search of his former apprentice, Master Depa Billaba, who may be responsible for war crimes.
The whole book is good, having the most important factors of a Star Wars novel: lightsaber duels, an exotic world to explore and a nice big battle. Mace's own shifting understanding of the Force adds a little edge to the story as he begins to see that which had driven his friend insane. Also, Kar Vastor's animal power is a perfect counterpoint to Mace's calm control. I almost felt myself jump for joy when Mace finally decided to stop playing by other people's rules and do things his way.
The fact that this story is a clear 'Heart Of Darkness'/'Apocalypse Now' rip-off is a shame as it makes the whole thing seem hollow somehow. Whilst it claims to be a Clone Wars novel, don't expect too much clone action as there is next to none, the story focusing instead on Haruun Kal's civil war. Ultimately, the way in which Mace is constantly wrong or defeated or tricked gives the impression the character had been betrayed.
A Star Wars must read, but not major in the scheme of the Clone Wars.