I had some problems to find into the narration and i think it's partially because Luceno did not really write a novel here but rather a documented history of the two Siths preparing for the Clone Wars and the Fall of the Jedi. Just like some of the movies on history channel it's interspersed with played out scenes but in the mainstay it's rather sterile counting of facts and integrating of as many storylines from the Star Wars franchises past as Luceno possibly could grasp, ending with the epilogue of the happenings during the Phantom Menace as crowning highlight of the Sith's ambitions.

In general i like such motifs and plot devices and i would have been glad to find as many comic and book story lines in these pages as humanly possible if only the main story would have had a tad more of an impact on me. I'm not sure if Plagueis is such an neutral character that i wasn't able to bond or if it was something about his motivation to be eeeevil which did not really behoove his persona as seen in the book. Palpatine/Sidious is a little bit better, but he owns only a distinct second place to his master in the course of the narration.

It's a good book to read if you're deep into the whole Clone Wars and before era or if you want to have a crude overview over the time but not invest in fifty comic books the TPM movie and half a dozen novels.
If you don't care much for the Sith or were already disappointed by all the "some time before the Prequels" Story's we've got to know over the time, then it is probably not your kind of story. And even hardcore Sith fans might be better off with the Bane franchise or the Lost Tribe books.