I'm not entirely sure how to rate this one, given that it was actually 3 books in 1 - so I'll split it into reviews of each book, and then my rating for the trilogy as a whole.
Brimstone - this book was arguably both the weakest and strongest in the trilogy. It followed the tried and true formula of previous books, in that it started with a murder, introduced a main character, and then Pendergast stepped in to help solve the mystery. I went into this knowing that something significant was going to happen that would introduce Diogenes, and spent most of the book wondering when that might be - this is what made it weaker, since I expected more of a set up to what I knew was supposed to be a significant antagonist.
I loved that we got to see the return of D'Agosta - hes absolutely one of my favourite characters in the entire series, and I love every book that features him. He's still determined, although a bit more distant and arrogant than we've seen him in the past since he took a voluntary demotion and separated from his wife. He was absolutely brought back to life by Pendergast though, and the development of their friendship was heartening and reminded me of some of the people I'm closest to.
Their adventure through New York and Florence was tense and interesting, and I will once again admit that I had absolutely no fucking idea who the killer was until it was revealed.
Bullard was a villain you love to hate, and an excellent red herring - I knew that he wouldn't be the killer, and yet he was such a smug, arrogant, controlling bastard that I was convinced that it had to be him.
Fosco was too clever for his own good, but I am glad D'Agosta got the better of him in the end.
I liked the full introduction of Constance too, even if we didn't get the full story of what happened to her until the next two books - she seems charming and naive, and she comes across as very other-worldly and out-of-place, which was exactly how someone of her condition should be.
The mystery was convoluted and I had no idea where it was going - there was a lot of music history involved with it, but it was explained enough that I didn't feel lost at all. The big reveal and explanation by Fosco was perfectly dramatic, and the escape from the castle was tense and kept me turning page after page until I was done.
The final few chapters and the epilogue tied together what I thought was an excellent story - as a standalone, this book would have been a solid 4.5, only missing that final .5 because it felt so much faster paced than other books that I felt like I was missing details because I was trying to keep up.
Dance Of Death - this was what I felt was the weakest book in the trilogy. The entire novel seemed very piecemeal? Everything we saw didn't seem to link to anything else, up until everything pulled together at the end. I think my main problem was that, for once, we saw Pendergast at a disadvantage and on the back foot, when we're used to him being the smartest person in the room - or at least putting it together in time to make sure the bad guy doesn't get away with it. It disappointed me, as much as it was interesting to see him on the losing side for once, it was clearly done with such malice, and didn't end with either brother having a clear victory, which obviously set up for the final book, buy it left me feeling like the novel was just unfinished.
I was overjoyed to see the return of Nora and Smithback, and as newlyweds no less! Its always such a joy coming back to the museum, and that we not only had those two back, but also Margo! She's absolutely my favourite character and to see her return after so long was a delight - she has grown in confidence and self-assurance, she's dominating at work, and she's clearly worked hard to put the events of the previous books behind her.
As we begin to see Diogenes plan begin to come into play, it definitely left me anxious for all my favourite characters - but the overwhelming relief and joy we get from D'Agosta at finding out his best friend is alive, felt so real and warm. It was a highlight of the entire series for me.
The hunting of Smithback by Diogenes, and his being saved by Pendergast was a great scene, as it felt very reminiscent of the first three books.
I admit that when Nora and Margo first bumped heads, I was a little disappointed and shocked at the antagonism between them, especially with how Margo got offensive in the meeting, because that's not a side of her we've seen before, but I did appreciate the apology and the growth of friendship between the two women after this incident.
The stalking of Margo through the new exhibition, and her attempted murder had me hanging on the edge of my seat - it was so reminiscent of the first book, and then we realise that it's Diogenes hunting her (at the same time we're switching back and forth between someone hunting her and someone hunting Smithback so we don't know who the killer is really after). The fact that I then spent the rest of the book, and half the next book mourning her is definitely one of the reasons this series is my favourite, because so few authors can make me that attached to a character.
The reintroduction of Viola, and both heists, was definitely an interesting part of the book for me. I know it was a big part of what Diogenes planned, and that Pendergast did what he could to save the people he cares about, but it very much felt like a petulant child throwing a tantrum - which I suppose it was, and it definitely reveals more of Diogenes true nature earlier than expected.
The arrest of Pendergast at the end was a sacrifice I hadn't expected, and it certainly highlighted the differences between the brothers and how they work.
Overall it continued the narrative and set up for the final book in this trilogy, but it did very much feel like that at points, a set-up, so I would probably give it a 3 overall, based on how bitty and incomplete it seemed.
The Book Of The Dead - I'm still not sure how I feel about this one. I felt like it was incredibly strong most of the way through, certain parts aside, but the ending fell a little flat for me.
We saw Diogenes in his alternate identity for the first time, and it was definitely chilling how easily he had everyone fooled and was able to manipulate those around him. It was genuinely scary to see the full force of his scheming and lies, and for most of the book I was trying to work out what he was doing.
His manipulation of Constance made me feel actually sick, and even though I knew he had to be lying, I still felt myself being swayed by him the same way she was, and it made the inevitable betrayal even more brutal.
D'Agosta was on top form in this book, from planning and helping with the heist, to joining with Laura to try and save everyone At the end - I liked his and Laura's relationship, and I'm glad she stepped up and made the right choice at the end of the book.
Nora and Smithback were also great as usual, with Bill working out that something significant was going on and triggering the whole setup without realising it, and watching Nora take charge of the exhibition and put together what was described as an incredible show.
The change in Lipper and Witcherly made the killings feel incredibly close and impossible to figure out how it was being done, although after the first book in this trilogy I did suspect it might be something mechanical. Witcherlys thought process leading up to the attack on Nora was terrifying, because it was so realistic of how some men see women, and I'm glad he got the ending he did.
Pendergasts prison break, and his subsequent rush to the museum and attempt to foil his brothers plans was tense and exciting, and the full extent of the journey into his mind palace to see what The Event was was thrilling. It gave us more insight into the family, and no doubt it was a horrific and traumatic experience for both brothers, but having Diogenes entire personality be reduced to brain damage and spite/vengeance felt a little boring considering everything else being so carefully thought out in each book.
The obvious indecision Pendergast felt when forced to choose between Viola and Diogenes was very strong, although I admit that I still don't understand the relationship with Viola. They met once, spent 5 minutes staring at each other, had another 30 second conversation Once he was arrested, and yet they're supposed to be so deep in love that it can't be explained? Considering how long it took Pendergast and D'Agosta to become genuine friends, this felt very contrived and as though it was only dropped in as another way for Diogenes to manipulate Pendergast.
The part where I felt like the book broke down a little was Diogenes escape and return home. Constance going after him was a surprise, and the fact that she seemed so competent after not having experienced the modern world before was stretching the bounds of belief a little bit, but then she's had a lot of time to study the Pendergast family, and to learn from both Enoch and Pendergast about how to plan and think ahead.
Diogenes race to get home felt desperate and paranoid, and while it was a little gratifying to see him be the one manipulated in turn, it also felt like his death was a bit of Deus Ex Machina which definitely left me feeling like there should have been a more significant end to him - although without seeing a body, I'm not sure how much I believe that he's really gone. I felt like Constance deserved an actual confrontation and to express her feelings, instead of reading the letter and immediately leaving to kill Diogenes.
Overall this book definitely dragged its rating down for me at the end, and while it did keep me turning the pages, I was just left feeling rather unsatisfied by it.
Together the three books make for an interesting addition to the series, and certainly expand on the lore of the universe the authors have created, but the rushed and unsatisfying nature of parts left me a little disappointed. I'd give it a 3.5 rounded up to 4, because I couldn't put it down most of the time, even if it didn't leave me as fulfilled as I'd hoped.