Time Untime sets the story about one of the demigod in Darkhunter world, Ren Waya, one of the ancient Guardian and possibly the first Darkhunter. There's another impending apocalypse incoming at the end of the year... (near my 24th birthday) and Kateri's life in danger. Kateri is a geologist who is the last in her line with the power of her ancestor to reset the timeline and thus prevent the onslaught of demonic apocalypse. Ren had to escort her to the temple before the time reached 11:11am on the 21st of December but before the bearer was revealed to him she was kidnapped to a hell dimension and Ren had to rescue her until both found out that they dreamed of each other killing one another for years.... everyday. 
 The book is a continuation of The Guardian (which can be set aside from the rest of the DH canon and thus a side-series) and most of the time, the author sort of recycled Acheron's story structure and things went very predictable most of the time. The tone of the story was more urban fantasy than paranormal romance despite the traditional pairing which is a pleasing read for me. But I do see the author is tiring herself out trying to do the alpha male and alpha female pairings AGAIN and the same romance AGAIN and a couple of steamy scenes which is quite the same as one of her Kinley Macgregor book. (please just stop) 
 I might stay reading the series for a couple books but I could only go far in this fandom. Considering I read her book around 2003-2004, so it does make me old right? 
 The story is set from second point of views of many characters like Teri, Ren and Acheron including Teri's continuous visions about Ren's checkered past as a human born from a warrior leader and a greek goddess. 
 Because the whole book happen in matter in a couple of hours that the romance part is very unrealistic. But both of them dreamed of each other's past for years. It does make sense about how they have deep connection to one another. But I'm unconvinced until the end of the book. 
 I do enjoy all the world building around this book especially with Nick popped into the book again. The earlier series focused on Greek storylines with Atlantean and Sumerian pantheons in the mix and with the addition Mayan lore the DarkHunter world really does become a verse within itself. I do enjoy the use of Native American culture into the mix because its something I rarely see anyone use it well enough. 
 I do hope Sherrilyn focus on her fresh sequels i.e. The Nick Chronicles or let one of these apocalypse unleashed in great scale for once and have one or two book couple die or something. I'd hate to see Sherrilyn Kenyon going to the road Christine Feehan did. Since both of them are sort of the mothers of paranormal romance for me, I dont want to be 30 and wondering why these PNR verse are still dragging on. 
 Irony that is, I started reading their books when I'm around 16 and I'm looking at the future and it doesnt feel good.