The String Theory trilogy gets off to a pretty good start. The first two books introduce and build on the mystery of a region in space where the normal laws of physics don't apply because of interference by Q-like aliens who turn out to be the Caretaker's people. Considering Janeway's determination to find the Caretaker's mate at the end of the episode "Caretaker," it always surprised me that so little was done with the idea -- just that one episode about Suspiria.
This trilogy makes up for that omission. It also brings in a lot of other continuity bits, setting characters up for changes in characterization in the TV series, especially the erratic Janeway of the last two seasons. It retcons the wretched return of Kes in "Fury" and gives Q another guest appearance. In short, it seems like exactly what the Voyager novel line needed: meaty big novels that take the show and its characters seriously, novels that are bound to appeal not only to hardcore Voyager fans but also those who like the characters and premise but think the TV series never lived up to its potential. (I'm in the second group.)
The first two books are solid work, though the use of string theory is ultimately about as important and meaningful as the use of dark matter in the Trek novels several years ago. It's just something neato and magical and unconvincing. But the nuts and bolts of it all don't matter in the first two books. In those, there are character conflicts and mysteries and tragedies.
I was disappointed by the third book, Heather Jarman's Evolution. It tested my willing suspension of disbelief a little too often, a little too much. The Doctor is presented as a photonic lifeform who can exist independent of his hardware and software. If the software isn't running on either sickbay's computers and holoemitters, or the ship's other similar hardware, or his 29th century lightbee (oh, wrong show, sorry), then the Doctor doesn't exist. Period. He's not going to be in some dimension where he can hear the strings of strong theory as an orchestra string section he can conduct, and he's not going to find himself in the body of an Ocampa several centuries back in time.
Granted, this is Star Trek, not Carl Sagan, but there's just too much magical stuff going on. You can get away with a lot of weirdness in the Q Continuum by explaining that the characters are seeing what's going on in a way they can understand -- but when you throw in a lot of stuff about the Caretaker's people, Q, Kes, string theory, and photonic energy, you can get seriously bogged down in layers of technobabble. You can even end up with a Nacene in human form complaining about the weakness and frailty of the body she's in, having just flown through space like Superman at a speed Voyager couldn't outrun and even being able to answer Voyager's communications while zooming along. No ship. Just that darn frail humanoid body.
So I felt let down by the story, but I was also disappointed by the prose. I remember thinking that Jarman's first novel, This Gray Spirit, was a little clunky at times. I don't remember having issues with the prose of Paradigm, her Andorian story. But the prose of this book struck me as being in need of a little more polishing. Sometimes Jarman tries to capture something of the quality of the viewpoint character's speech, most noticeably in the formal and stilted Seven of Nine sections, but then there'll be a phrase or a sentence that jars with the tone. There are ill-considered word choices, with simpler words avoided in favour of fancier ones. Or words that are perhaps too informal. Or both, when Jarman refers to alleviating someone's mopeyness. Jarman also repeatedly uses the kind of tactic I might have used as a kid desperately trying to reach the number of required words for a school essay, stating not only what's implicit but what's obvious. Example (paraphrased): "she had only a few minutes to make an important decision, not an indefinite amount of time." A few minutes is not an indefinite amount of time, and most readers probably understand that. It's like saying, for example, Kes wore a red dress, not a green one. The second clause adds no information. It just fills up space.
There's also too much of what seemed like poor grammar as opposed to stylistic choices: subject-verb agreement issues, run-on sentences, and subordinate clauses taking over sentences. (This glass house has a lovely view. Hey, look, stones! Want to throw one with me? Never mind.)
The book's not all bad; the Harry Kim and Tom Paris and Q storyline has some entertaining moments, and I'm glad to see Kes again. I can imagine a lot of fans thoroughly enjoying the book. But for me, it was a little too reminiscent of the bafflegab and confusion that too many Voyager episodes suffered from.