Finally obtained and finished Summon the Thunder.
Easier said than done - on both counts, sorry to say...
If there's one word to describe StT, it's "excessively verbose and redundantly self-repetitive". Uh, I mean "talky".
There's a lot happening in that book, but most of it has already happened once, in Harbringer. Several of the key elements here are mere repeat acts: Quinn's interaction with his various masters, Xiong's research, Sandesjo and T'Prynn's spooking, Jetanien's tirades. There is a big battle involving one of Vanguard's starships, but it reads much like the final fight of the Bombay: redshirts are introduced and fleshed out, and then that flesh is put through a grinder, while the characters familiar from the previous book soldier on. The nuances and the different characters don't quite manage to give this episode dramatic independence.
There are novel and quite outstanding elements to the book, of course. We see the Klingon and Tholian points of view for the first time. Or, rather, in StT we see these elements twice, when in Harbringer we saw them "halfce". Where Mack leaves 50% of an event to imagination, Ward&Dilmore spell it out once, then repeat the description or revelation or introspection in a succeeding paragraph, sometimes running out of synonyms in the process.
Still, we do finally learn solid facts about the Tholians. And the three-way battle between the Klingons, their subjects, and the Sentinel's forces is sheer magic, and a delightful contrast to how our Starfleet heroes fared in a similar fight earlier on. A little less Klingonese and a little more character interaction would have made it even more interesting, though.
Contrary to some of the opinions here, I found the Romulan viewpoint beneficial to the overall story. While their invisible presence and ultimate demise affects nothing, it also nicely accentuates the fact that nothing outstanding really happens elsewhere in the story, either. The Romulans are silent witnesses to the featureless inevitability of it all. Whoever doubted that Starfleet research would unravel the mysteries of the meta-genome? Was there any question that the disagreements between the Empires would escalate to open hostilities? These things happened, not because or despite our heroes were involved, but because they were fated to happen.
As a necessary interlude to a greater story arc, StT serves with valor. But exactly because it is part of such an arc, it seems highly superfluous that it would recap past events at all. If people don't buy Harbringer either before or after reading StT, they aren't interested in the overall story anyway; if they do buy it, they will be annoyingly spoiled by the exposition in StT. This book isn't appetizer, it is sheer filling. After the reading experience, I'm all the more in favor of Mack's "halfce" writing style.
Timo Saloniemi