Sloan McPherson, a Florida police diver with the now disbanded Underwater Investigative Unit, has been temporarily reassigned to a land-based unit, and when the body of a young woman is found along the shoreline, Sloan is called in to consult. Even though her colleagues are eager to write this off as an accident or suicide, she suspects murder, so she reaches out to a cantankerous homicide detective with a reputation for volatility to help her prove it.

The main reason I enjoy this series so much are the tense spots Sloan and her team mate Scott find themselves in when they dive, so I was disappointed that this took place almost entirely on land. That being said, this series has great characters and it’s well written, so I still enjoyed this book, and the author teases that Sloan and her UIU team mates may be back together and in the water in the next installment, so I’m looking forward to that!

Thomas & Mercer via NetGalley kindly provided me an ARC of this book in exchange for an honest review.

This series has been a favorite of mine from the beginning and Mayne’s newest addition doesn’t disappoint. Mayne’s characters are complex and endless interesting; I love the introduction of Gwen, who’s a great foil to Sloan’s character. Sometimes a police procedural can be plodding but that isn’t the case here, the plot twist and turns at a non-stop fast-pace that is un-put-downable. I will say I missed not seeing the rest of the Underwater Investigation Unit but in the over-arching plotline of the series it makes sense. Can’t wait to see what’s next for this great series. While this is fourth book in the Underwater Investigation Unit series it could be read as a stand-alone but you’ll want to catch up on Sloan’s previous investigations, so be sure to pick up book one, The Girl Beneath the Sea.

I received this eARC thanks to NetGalley and Thomas & Mercer in exchange for an honest review. Publishing dates are subject to change.

Sea Castle by Andrew Mayne is a very highly recommended procedural/psychological thriller. This is the fourth novel in the Underwater Investigation Unit series which also includes The Girl Beneath the Sea, Black Coral, and Sea Storm, but it can most definitely be read and relished as a stand alone novel.

Police forensic diver Sloan McPherson of the currently inactive Florida Department of Law Enforcement Underwater Investigation Unit is called in to assist when a young woman's body is discovered on a Fort Lauderdale beach. Floating near the body is a bag containing the woman's clothing. Sloan is positive it is murder and the dead woman, identified as Nicole Donnelly, was strangled. The rest of the team of investigators have questions and doubts after the autopsy. Sloan decides to pursue the case, which leads her to Gwen Wylder.

Gwen is a rude, obsessive, intelligent Miami homicide detective. While she looks at Sloan's case, she demands Sloan look at two different cold cases she is investigating. As Sloan looks into the cold cases and finds new clues and answers, another woman disappears. Sloan and Gwen form a fractious partnership trying to find the person who is killing women.

Sloan and Gwen are both wonderfully strong and fully realized female characters. Their backgrounds are explored within the plot and the development of their characters continue throughout the novel. As the narrative progresses there is a character presented that will confound and throw most readers off course.

The writing is excellent in this fast-paced engrossing procedural that reads like a psychological thriller. I absolutely loved this entertaining and gripping novel and need to look at the other books in the series. The twists and new revelations in the plot are focused, surprising and unique. I found myself glued to the pages and totally immersed in the story. Even though there isn't a lot of underwater investigation in Sea Castle, there is still a fascinating and exciting investigation related to the ocean. The final denouement was a surprise and unexpected. Sea Castle is an outstanding novel with a captivating narrative!

Disclosure: My review copy was courtesy of Thomas & Mercer via NetGalley.
The review will be published on Barnes & Noble, Google Books, and Amazon.

I received an ARC through "NetGalley" and I am voluntarily leaving an honest review.

The story begins with Sloan being called to the beach where a body has been discovered. It appears the person has been killed with a rope around her neck. Sloan spots something in the water and goes in the water and recovers a bag where clothes are discovered and the assumption is that they belonged to the dead woman. The M.E. places the body was in the water for around 24 hours. Sloan believes that the woman was not in the ocean for that length of time. Sloan works to prove her theory. She later gets teamed up with Gwen, a detective in Miami who has been banished because of her attitude. Gwen and Sloan begin looking into the beach victim's death. Gwen convinces Sloan that the case of the drowning is related to something that Gwen has been working. Gwen even goes so far to try and convince Sloan that a certain individual that has been missing will be dead in three days. Gwen and Sloan convince their bosses to run a picture of this woman. Things blow up when the victim shows up at the police station where she lives.

Sloan and Gwen are able to bring her back to Miami where information is obtained which relates to the person responsible for the multiple killings that have occurred. In learning of a vehicle that might be involved, they meet a unknown party who tells them that she was kidnapped. They eventually gather enough info that they finaly have a suspect identified.

To learn what information was obtained from the person that was brought back to Miami, who the new person that Gwen and Sloan found which eventually provided them with a potential suspect plus what Sloan wound up doing to protect this last victim, then you need to read this book. The ending will cluear up everything.

I didn't realize when I requested this book that it was part of a series, but I really enjoyed the book regardless. A fun adventure!

Sea Castle is the fourth book in the Underwater Investigations series. In this book, the UIU department has been temporarily placed on hold due to investigations and politics. Sloan is currently working with the FLDE. Because Sloan works differently than everyone else, no one wants her on their team.

Sloan gets called out to the beach after a dead body has been found. They work the case but have no leads. Testing a theory about how long a body can be in the ocean before it attracts predators, she manages to upsent her boss. If they can't find anything definitive then they need to move on until something new comes up in connection with the case.

Sloan is teased about becoming another 'Wylder' and has no idea who that is. She locates Wylder who is similar to Sloan but definitely angrier. Before long Sloan is transferred to Wylder making it a team of two in cold cases. Wylder hands off a cold case to Sloan to take a look, while Wylder looks and the case of the girl on the beach. Sloan brings back her evidence to Wylder who is quietly impressed. Sloan is given another case but gets upset that they are not working the case she brought to Wylder. Wylder suggests the cases might be linked but Sloan will have to find the evidence to prove it.

This was an intense psychological thriller. Sloan and Wylder are very much alike. They see threads that no one else sees, they pull and pull until they get to the bottom of it. Sloan is a strong-willed woman, but she definitely has a sensitive side about the people close to her. It was interesting to follow the threads with Sloan. Her mind just works differently and doesn't accept things at face value, she needs to prove them right or wrong. I thought that this was an interesting read and am looking forward the next installment in the series.

As a Florida native, I love this series. There are similar style books but none with a strong female lead. I also love the Underwater Investigation Unit, and this book seriously lacked underwater scenes. It makes me nostalgic for the first book. I do love that in this book we meet Gwen, a very smart but highly unliked female character. She’s a very interesting character to add to the mix. It’s not my favorite of the series but well worth the read! Thank you NetGalley for the gifted copy!

I was completely lost in this book. This was the first book I’ve ever read from this author. I had no idea there were 3 more books to read before this one. I could read them because they aren’t on kindle unlimited. I had no choice but to DNF this one. I wish I didn’t have to but I had no idea what was going on.

Changed to 3 stars because I loved the cover

In the 4th book of this series, Sloan McPherson is called to investigate the death of a young girl who washes up on shore. Sloan is a very interesting character and I've very much enjoyed her previous adventures. The Underwater Investigation Unit (UIU) team that Sloan is a member of is currently on hiatus so Sloan has been assigned to a supervisor who is not much enamored of Sloan. While pursuing the investigation of the dead girl, Sloan teams up with Gwen Wylder, an older and very difficult detective to solve this and a couple of cold cases.

In this installment, except for a brief swim in the beginning, Sloan spends little or no time either in underwater investigation or with her UIU teammates. I really liked this unique aspect of the series so I found this lack a bit disappointing.

This was my least favorite book of the series and at times, I felt as if I had missed something pertinent to the plot. It could have been the formatting of the uncorrected proof which was very distracting but overall, I still enjoyed Sea Castle. Andrew Mayne writes solid mysteries with unusual plots and characters and I look forward to his next book. Thanks for Thomas & Mercer and NetGalley for an advance copy.

I'm always in for a good crime thriller, and after enjoying the first three books of the Underwater Investigation Unit series I simply had no other option but to jump right at the opportunity to read book four. I love the fact that this series has a Florida police diver angle, which is something you don't see every day. On top of this, the books tend to be both intense and basically an action-packed rollercoaster ride; my kind of thriller indeed and scoring very high on an entertainment level! Sea Castle did start out slower than expected for me, but the second half soon came just as intense as I've become used to with this series.

This series has a different vibe than your typical police investigation thriller, and this is partly due to the police diver angle and partly due to the fact that Sloan McPherson has such a colorful background and isn't afraid to break the rules. I do have to say that Sea Castle didn't have the same feel as the previous books, which mostly has to do with events in the previous books, the fact that there isn't much actual diving going on in this book and the fact that the unit Sloan was part of is currently suspended. The first part did read more like your typical detective thriller as a consequence, and it was a lot slower than usual... Not bad, just different than I expected. This doesn't say that way though and once Sloan meets Gwen and they get some balls rolling, things start speeding up fast.

I always love spending more time with Sloan, although it's a shame we didn't see much of George Solar and Scott Hughes in this book. Gwen made for a great substitute though, and her attitude and manners made for some very entertaining reading indeed. I also loved the growing connection between Sloan and Gwen and the way they investigated. The occult/cult element can go both ways for me, but I did like how it was incorporated here... The whole manipulation element was explained very well. And there were definitely multiple twists I never saw coming!

The writing style flows easily and is simply addictive; the pace might be slower initially, but especially the second half is fast and exhilarating. There is so much action and danger lurking around every corner, and Sloan is always there using her instincts to help save the day. The lines between action and crime thriller start to blur especially in the second half, and it's the perfect balance for me as well as extremely entertaining. The story also ended with some excellent news, and I already can't wait what the next book will have in store. If you like your thrillers lightning fast and action-packed, this is definitely a series to put on your radar.

This series gets better every time! Sloan is a diver and a police officer, a mother and an intelligent woman. Her usual team is in a bit of trouble with some red tape politics so she’s stuck working cases. Having been called out to a murder, she realizes somebody else could help her out. Enter Gwen, she’s bitter, hated, despised and she loves it. Oddly enough Gwen and Sloan make a fabulous team because Sloan knows how to read Gwen. Their relationship kept me more interested than the actual cases they worked on. The cases were intriguing and no problem for Sloan to solve, but together they found a serial killer. The entire series is worth reading and I highly recommend it, however this one can be read by itself. I received my advanced copy from NetGalley and gave this review voluntarily.

I received an advance reading copy of this novel for review from the publisher, Thomas & Mercer, courtesy of Net Galley. When I started reading, I didn't know it was part of a series, but it did not hinder the pace of the novel. The author does a good job throughout the book to provide character back stories.
The book starts with a naked female body washed up on shore in the middle of a turtle breeding ground/nature preserve. Florida Department of Law Enforcement (FDLE) diver Sloan McPherson is called in to assist and promptly dives into the water to retrieve a floating plastic garbage bag, which is later discovered to contain the deceased's clothing and personal items. She is later identified as Nicole Donnelly.
The body is intact, no marine activity (in the midst of shark territory), so the investigation begins on where & when the victim was killed and dumped.
Sloan's unit, the Underwater Investigation Unit, is scattered, waiting for disposition after internal investigations into previous cases are concluded. This leads to Sloan coordinating with various law enforcement agencies, ending up at the "office" of Miami detective Gwen Wylder.
Gwen is labeled by her department as an overzealous conspiracy theorist who is demoted to the basement with cold cases. When Sloan enlists Gwen's input and assistance in Nicole's case, Gwen hands her 2 cases in a row and makes her solve them. It a test, and Sloan passes.
Gwen's theory involves a potential serial killer using various pseudonyms and technology, channeling psychobabble and a dash of the occult to groom possible victims via the internet.
Gwen identifies another potential victim in Carla Burgh, who goes missing. The agencies don't believe her theory, so Sloan & Gwen are flying solo. As they track the killer, another victim, Riley Devereaux, is rescued and questioned for leads.
What follows is a methodical procedural (meant in the best possible way), taking our protagonists from internet trolling to engaging psychologists to deprogram the victims with a side helping of internal law enforcement territorial politics.
The denouement reveals the extent of the killer's manipulation and is satisfying.
I'm definitely going to download and read the first 3 novels of this series. This book will be released on February 21st.

Sea Castle is a fast paced police suspense by Andrew Mayne. It took me a few chapters to really get into the book but once I did, I couldn't put it down. The plot and the characters were interesting, well written with lots of vivid details and background information. I sort of saw the plot twist, near the end, but that didn't impact my enjoyment of the book, overall.
A girl's body has been discovered at a Fort Lauderdale beach and Sloan McPherson, of the Underwater Investigation Unit, has been brought in to help. It looks like murder, to her. There are just way too many loose ends for Sloan's comfort. It looks like more than an accidental drowning to her.
She decides to seek out the infamous Miami Homicide Detective, Gwen Wylder. She agrees to help but it's conditional on Sloan helping her on some past cases that have haunted her for years. As they get deeper into the old files, they start seeing a pattern and then things get weird.

Here goes my first review! This was my first book by Andrew Mayne! I was unaware that this was a part of a series at first but I decided to read it anyway and I’m glad I did! Though I didn’t get to know the main character in previous books, I felt that I didn’t need to read them to know her in this one. I was immediately intrigued when we opened with a body washing up on the beach. I love diving right in! The story progressed quickly with the link to other deaths and disappearances and we were soon on our way to finding the serial killer. I liked the cult aspect and I never would have suspected the ending!

She was laying on a beach with a rope around her neck. The forensic team felt she had been in the water for at least twenty hours. Sloan McPherson could not reconcile that in her mind with the condition of the body. Nothing had been nibbling on it!

Killers are not always prudent. Sometimes it seems like they are trying to get caught. Why would someone leave the victim’s clothes and other crime evidence in a black plastic bag near the body? And although the victim was chocked with the rope attached to her body, why were there no self-defense marks or evidence of a struggle?

Andrew Mayne has put together a very illuminating study of killers and the law enforcement personnel who set out to apprehend them. This is a very good example of fine police procedural work. The book is witty and at times disarming as the various characters are developed. The end result is a very engaging and entertaining book that I couldn’t put down. 5 stars – CE Williams

Sloan McPherson is a police diver with the FDLE (Florida Dept. of Law Enforcement) with a perseverance to solve crimes and bring justice to the victims. When a woman's body washes up on the shore, she immediately dives in - literally. Gathering evidence from the area, she presents it to the accompanying police and detective agencies though her colleagues try to shrug it off initially. Sloan, determined to solve the crime and believing something isn't right about the case, stumbles upon an old detective named Gwen Wylder, who has more or less been shrugged off by her colleagues due to her obsessive and sometimes combative nature. Working together, Sloan and Gwen come to rely on each other for helping solve the murder of Nicole Donnelly, but what else will they uncover?
~~~~
The one thing I disliked about this particular novel was I felt like there was a bit less of Sloan's diving work compared to other novels. Part of my main draw into this series was the "different" type of detective work done - and by a female, at that. But for some reason, it felt minimized in this novel. I also didn't care for the increased emphasis on being part of/working with the police department rather than working more on her own (and with Solar). So I'm interested to see where the next novel takes this, and if it's more like her (and the authors') "older" work or explores a new avenue.

Overall, I still enjoyed the read.

Another propulsive thriller by Andrew Mayne. This is the fourth in the Underwater Investigation Unit Series and it is as addictive as the previous volumes. Sloan McPherson helps recover a dead body and, as always, she sees something the rest of her colleagues don’t. Hughes and Solar help her along the way but, since she’s technically on her own, she gets to work with a new partner. Gwen Wylder is what Sloan would be without her support network, a cop with good instincts who’s been shunned by everyone because of her rudeness. They have many funny dialogues and their chemistry is explosive while they search for a serial killer that no one is sure exists. I missed Sloan’s usual team and her family, who appear very little, but I enjoyed getting to know Gwen. I really liked the twists, even if I saw the big one coming. This is pure escapist entertainment.
I chose to read this book and all opinions in this review are my own and completely unbiased. Thank you, #NetGalley/#Thomas & Mercer!

It's only cold if you're standing still.

Special Agent Sloan McPherson knows cold cases. She's part of the Underwater Investigation Unit of the Florida Department of Law Enforcement. Her team has been set on the sidelines for a while. Sloan has been relegated to leaving footprints on land for the time being.

Let's introduce you to Sloan. Sloan's father is a treasure hunter in Florida and is more fish than mammal. She has a thirteen year old daughter, Jackie, with her partner, Run. While her father is more fish, Sloan is more bloodhound as she's cracked open some of the most difficult cases on record. She's a dynamo, but she's also painfully human and she's well aware of it.

Latest case: A body of a young woman has been found dead in the waters near the coast. The woman had a rope tied around her neck. Nicole Donnelly was from Atlanta. Tourist or here for other reasons?

Now here's where Andrew Mayne flips the script. It's been suggested that Sloan work with Miami Homicide Detective Gwen Wylder. Wylder has quite the reputation on the force. And that reputation has her missing a few nuts and bolts in the upper shelves of her mind. Wylder is tredding water in the department's basement awaiting retirement. But Wylder is not going out without making inroads into stacks of cold case folders on her desk. A partnership made in Heaven or more likely Hell?

Andrew Mayne has created two cast iron women forged in different manners. We'll experience Sloan's outright honesty in dealing with Wylder and Wylder's cantankerous, cutthroat attitude with Sloan. Mayne knows how to insert snappy and snarky dialogue in just the right spots with humor sometimes leading the way.

Sea Castle is one tightly wound psychological thriller with all the bells and whistles. Andrew Mayne is known for his expertise in carving out characters with well-honed hammer and chisel. And it all works like a fine-tuned machine. Sea Castle can be read as a standalone. We've got another winner in the talented hands of Andrew Mayne.

I received a copy of this book through NetGalley for an honest review. My thanks to Thomas & Mercer and to the talented Andrew Mayne for the opportunity.

A nice addition to the series but entirely enjoyable on its own. It's well written with a good twist - and the setting is terrific. Thanks to Netgalley for the ARC. A good read.

The fourth underwater investigation series finds Sloan investigating after a woman mysteriously washes ashore dead. While other investigators think it could be suicide, Sloan is convinced its murder. When she gets help from a cold case detective, she discovers there could be a serial killer hunting along the interstates of Florida.

I feel like it took a little too long to get to the serial killer angle. There was a little too much of other stuff that I didn't think was needed when we could've been at the extended investigation earlier.