The Tomol saga picked up the pacing in this book, although the authors (not David Mack who wrote the first book) deemed fit to recount the backstory on several occasions, apparently for the benefit of those who read Book 2 in isolation. This interrupted the natural flow of the story at times.
There were also some odd phrasings that went undetected. For example:
“He [Dr Leone] knew from the Sagittarius reports that the Shepherds were what the Tomol called the Preservers, and that the wordstone was the obelisk the scout ship’s landing party had found in the underground caverns.”
The Tomol wouldn’t have known about the existence of the Preservers, unless some Starfleet personnel told them so, which I suspect would be against the Prime Directive. Thus, the sentence should instead be:
“He knew from the Sagittarius reports that the Shepherds referred to by the Tomol were actually the Preservers….”
Or (a bit awkward):
“He knew from the Sagittarius reports that the Preservers were what the Tomol called the Shepherds….”
Then, there’s a big plot hole. Why didn’t the Preservers’ defense mechanism take action in the first book when Nimur went on a rampage and when the Sagittarius was basically trading fire with Homghor within the orbit of Arethusa?