When The Undead Pool was originally published back in 2014, it was planned that the series would come to a close after 13 books. This being book 12 would indicate we're nearing the end of the story arc. But woohoo! Ms. Harrison is publishing a return to the Hollows book later this year titled American Demon so hopefully we won't be saying goodbye to Rachel and Jenks for some time yet. :)
In The Undead Pool, Rachel is again out to save the world, with Trent right by her side. I don't want to give away too much, but if you've been watching the relationship (or previous lack thereof) between Rachel and Trent, you'll definitely be surprised how things develop here. Suffice to say, I was gleefully happy with the direction it's taken. ;)
Overall, this was a fantastic addition to the series—fun, fast-paced, and exciting. Highly recommended!! But definitely start with Book 1, Dead Witch Walking.