Honestly, I skipped the middle 150 pages when I realized it was literally all flashbacks. Went to the last chapter with a flashback and read the big revelation regarding the Fountain. I was fine for the rest of the book, which tells me those pages really weren't necessary for the actual plotline other than for padding and adding unnecessary dramatics between the love triangle. 
 The ending didn't help my overall impression. For such a dire situation, according to the MC, there was literally no sense of urgency. From anyone. (view spoiler)[ Scarlet and Tristan stopped for a sex break for pete's sake. (hide spoiler)]. Thoroughly unimpressed.