Review: The Agency: The Traitor in the Tunnel

Queen Victoria has a little problem: there’s a petty thief at work in Buckingham Palace. Mary Quinn takes the simple case, going undercover as a domestic servant. But before long, a scandal threatens to tear apart the Royal Family.
One of the Prince of Wales’s irresponsible young friends is killed in disgraceful circumstances. Should the Queen hush things up or allow justice to take its course? Mary’s interest in this private matter soon becomes deeply personal: the killer, a drug-addicted Chinese sailor, shares a name with her long-lost father.
Meanwhile, James Easton’s engineering firm is repairing the sewers beneath Buckingham Palace. Trouble is, there’s a tunnel that’s not on the plans. Its purpose is unclear. But it seems to be very much in use.
These overlapping puzzles offer a perfect opportunity for Mary and James to work together again… if they can still trust one another. This is Mary’s most personal case yet and she has everything to lose.

I love things all Victorian, especially when the story takes place in London, England.  There's just something I find so fascinating about that time period.  The technology that came out of there (like the flush toilet!) was booming.  London was a bustling city while everything around it was growing (like their sewer system!).  And being the nerd I am, I know much more, but I'm not going to bore you all. 
Although, here's an interesting tid bit!  Corsets were not leather cages meant to make women pass out!  That was in the seventeen hundreds where tight corsets were in high demand.  Also, people did not shower and when they went to these lavish parties, everybody would pour on noxious perfumes to cover the stench--which did not help a whole bunch.  And on top of that, rooms were not the highly ventilated rooms we have today.  Corsets was actually like wearing a bra in present time.  Like seriously, women had to run up and down those tiny servant steps to get the job done carrying pales of water and other things.
So maybe I know a bit about the seventeen hundreds, too. *smiles sheepishly* 
Talking about this book, though, I thought it was the best out of the entire series.  The other books I gave four stars to, but to this one, I gave it five.  It was just great! 
The one thing that has always bothered me was James and Mary's relationship.  I loved how they always quarreled and investigated different cases together.  But then at the end of the last book, they broke things off with each other!  I was heart broken!  I was all, "But they were meant to be together!" and would wail, "Whhyyyy????".  It was not a fun time waiting for this baby to come out.  Not at all.
In The Traitor in the Tunnel, I feel as if Mary Quinn possesses an independence she didn't have in the other books.  This assignment is technically her first as an agent, but she's been on her own for a while now.  She was strong and knew what she wanted.  She's pretty bad ass for a teenager in the Victorian era, just saying.
The mystery was something that truly stumped me.  I could not figure out it for the life of me.  There were barely any hints left behind and I could only keep guessing.  But in the end, boy, was I surprised to find out who it was.  So mystery wise, awesome.
Honestly, I wish the Mary Quinn Mysteries didn't end with this book.  I feel as if this series could keep on going on.  It has the potential for it.  I'm not imagining it as a fourteen book-long series, but maybe a five or six book series?  I can't get enough of Mary and the ever charming and dapper James Easton!
So, in all.  This lovely is five stars.  The writing was perfect, the setting was vivid, and the characters were dimensional.  Very dimensional.  I'm sad to see this series go, as I always am when books reach their end.  But there's something about Mary Quinn I could keep reading about.  In all, however, it was a great end. 
Happy reading, all!