A decade into Paul's reign over the known universe.  He's turned into a living god, and in his name millions have been killed in a continuing Jihad.  He has as many worshippers as enemies, the latter lead by the Bene Gesserit and the Guild, with some secret assistance of the Tleilaxu. 

He is married to the daughter of the former emperor, but his true love is Chani.  She hasn't given him a heir yet though, and the pressure from various groups mounts to find another solution.  A plot or just a practical issue?  The Tleilaxu give him a ghola (a revived corpse) called Hayt in which Paul recognises his old weapons master Duncan Idaho.  Present or trap?  Hayt has no memory from before his revival, though that memory is somewhere in his genes.  Paul's sister Alia, conscious before being born, has her mother's memory of Duncan Idaho as he was, and she too recognises many things in his moves and tics.  She falls for the Ghola.

Meanwhile Paul is struggling with a horrible choice about his personal future and that of humanity.  The Spice has given him insight in many possible paths, but the political forces and the plots in plots around him give him only two real choices, neither of which attract him..

If you expect an adventure novel like Dune was you're in for a surprise.  Hardly any trips even outside the city.  In stead we are confronted with a hesitating and doubtful Paul, who has a choice like between pest and cholera.  No matter how often he searches the future, certain parts stay hidden, and the parts that are visible range from personal tragedy to outright horrible bloodshed.

Not that the absence of adventure makes this story any less interesting.  On the contrary I would say.  We are encountered with the loneliness of the living god, and with the heartbreaking choices a person in that position has to make.  And at the same time there is place for love and romance, yet alternated with bitterness about what is being done in his name.

And the absence of adventure doesn't mean the absence of a plot - oh no.  With surprising twists and turns, even when you're made part of the plotting, you don't know the true meaning behind every meaning, scheme behind scheme, before the plans are really executed.  The ending is a masterly example of this.