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.

This book was so well written and had so much thought put into the characters and how well they are portrayed. Sloan is forever the hero, in so many ways than I could ever touch on. She is the ultimate female that every girl should have as a role model in their life. Granted her decisions aren't always the best. But she always fulfills what she aims to do in order to get the results she wants.

After the UIU are disbanded in the mean time, she is working with the FDLE. Needless to say no one else is super excited to have such a rockstar in their department. Till she is thrown into a working relationship with the toughest woman to get along with, it was all daisies and butterflies.

Now she has been put into a position that she doesn't necessarily want to be in, but here she is anyway. She starts off running and brings to cold cases closer than ever to being solved. Only the last few pieces, until she starts seeing there is a pattern where there shouldn't be.

With the start of a new case she is off to be her devil may care self to solve the crimes at hand.

I really enjoyed this book so much, and I absolutely loved that there was another character that we got to know more of even if she wasn't the character anyone expected. With the twists and turns of this novel I can't imagine Sloan being anyone but her. Forever smart as a whip and always willing to challenge the status quo.

Good, solid mystery with interesting characters.

This is the first book I’ve read by this author. It was interesting, the characters were unusual enough to keep my attention, and the twist at the end came from nowhere. A bit choppy but not bad.

Thanks to the author, publisher and NetGalley for the opportunity to read and review this book, but my opinions are my own.

We live close to the beach and go several times a year. Our beaches are fairly rocky, so we do drive a few hours to a less rocky, and sandier beach once a year and stay for a week.

Sloan McPherson of the Underwater Investigation Unit is called to consult on a woman who has washed ashore in Fort Lauderdale Florida. Sloan reaches out to Gwen Wylder, a disgraced police detective who is wickedly smart. Gwen promised to help Sloane, but only if Sloane helps her with a troubling case. As the file comes together Sloan and Gwen are determined to track down the killer before things get even more out of the ordinary.

This was a solid read in the Underwater Investigation Unit, this is the fourth book. I read this as a stand-alone and am excited to read more of the series as in this one, Sloane acted alone, without her team. I think if the team would have worked together on this one, it would have been more enjoyable, but it was a solid enjoyable read overall. I appreciated how strong will and determined Sloane and Gwen both were. I’m a sucker for a strong female main char

Check this one out on February 21st if you’re looking for a heart pumping thriller. Thank you to @netgalley and the publisher, Thomas & Mercer, @amazonpublishing, as well as the author for this e-arc in exchange for this honest review.

I love the audiobooks by Andrew mayne but the book was harder for me to be interested in and read. I would prefer the audio but the book was well written and I love the continuation of the story. I will definitely keep reading his books.

It took me until this book to realize that the author is THE Andrew Mayne from Shark Week. But Sea Castle is another great book in this series. Sloan McPherson's team has been shaken up and she's forced to work with another woman that "could be" her in 20ish years. Mayne does a great job with the character depth on this installment of the series and leaves the reader capitvated up until the very end.

Sea Castle by Andrew Mayne is a mystery based on the adventures of heroine Sloan McPherson and the Underwater Investigation Unit (UIU). This is the fourth book in the series. In this installment, Sloan and the UIU are in hot water and temporarily working in other units. Sloan and her new supervisor have a love/hate relationship impacting Sloan’s ability to follow her gut and work on active cases. Instead of working with her UIU partners, Sloan is paired with the neurotic and somewhat dislikable, Gwen Wylder. Together, they work to solve two different cold cases.

This installment was enjoyable with an interesting plot, but of the four in the UIU series, this was my least favorite. I missed the underwater adventures of Sloan and her partners while investigating crime. Additionally, we rarely saw Sloan’s UIU partners in this installment. Instead, we were privy to Sloan’s strained working relationship with Gwen.

Overall, Sea Castle was enjoyable, I recommend this book and the entire series for any fan of mystery! Thank you to Netgalley and Thomas & Mercer for an advance copy of this book.

Happy Sigh! Andrew Mayne Entertains! Yes with a capital E. I am always intrigued and invested in the characters. The UIU was mostly a Sloan McPherson story as UIU is temporarily disbanded. But her team is mentioned to remind us she is just on loan to another department whose leader thinks less is best. She is also mostly on land in this book. I was okay with that as I read this series for the UIU team and Sloans family. Sloan is called to a body dumping where the signs point to suicide, but something seems off. Instead of going for the easy answer Sloan starts investigating. In between the usual digs from the police force she keeps hearing about Gwen Wylder. Asking questions she learns Gwen is super smart, but appears to be vindictive and has been sent to work cold files in the basement. Sloan goes looking for her and we are off. One minute you hate Gwen and another you feel sorry for her. Sloan does her think out side the box, investigate and pull on every thread. I was thrilled to receive this arc, rewarded with entertainment and excitement for the next book in this series! I freely volunteer my thoughts and opinions! If you like being entertained grab this book. #seacastle #underwaterinvestigationunit #andrewmayne #thomasandmercer #netgalley

First and foremost, a large thank you to NetGalley, Andrew Mayne, and Thomas & Mercer for providing me with a copy of this publication, which allows me to provide you with an unbiased review.

Andrew Mayne returns with his somewhat unique series, set in the heart of Florida. Using a forensic diver as his protagonist, Mayne is able to tackle a different angle to most crime thrillers I have read, while keeping the reader intrigued until the final page turn. Adding some serial murder and cult-like behaviour, Mayne shows that he has all the ingredients for a great novel, sure to keep the reader enthused.

Sloan McPherson has made quite a name for herself in Fort Lauderdale as a member of the Underwater Investigation Unit’s forensic diver. When the body of a young woman’s body is found along the shoreline, Sloan immediately presumes it’s murder, while others ponder the possibility that she might have committed suicide. The clues do not make sense and Sloan is baffled as to what she is seeing in front of her.

Sloan begins poking around, but she is stonewalled by the authorities, as they are sure this was a simple miscalculation by a novice swimmer. Enter Gwen Wylder, who is quite rough around the edges and an outcast with the Miami Police. Wylder is happy to help Sloan, but for a price. Sloan must help by offering her own insight into some cold-cases that Wylder has been amassing, all part of what could be a serial killer who has been conniving while they traipse across Florida without detection.

As Sloan soon sees, her victim fits perfectly into the larger case study and there is proof that a killer could be travelling across the state, killing young women. Another woman goes missing, leaving Sloan and Wylder to race out so they can stop a killer from striking again. As things get more intense, both women find themselves involved in something they could not have expected, where they are not able to extricate themselves with ease. Mayne creates an intense story and keeps the reader hooked with some of his unique perspectives throughout.

It was the first book in this series that alerted me to the work of Andrew Mayne. Since then, I have not been able to get enough, having devoured a few of his series, while always remaining in awe. Mayne knows what he’s doing and keeps things fresh, unique, and on point. Whenever I see a new publication of his, I cannot help but rush to get it, knowing that it will be a stellar piece of writing.

Mayne develops his narrative in such a way that the reader wants to learn more. He knows how to present a tale that balances the criminal element with some strong backstory, all of which is essential to the final product. Great characters, some of whom build their development throughout the novel, provide the reader with some entertainment as they continue with the journey. The forensic perspective, mixed with the plot development, offer something unique, though this book steered away from underwater exploration and more to the chase for a killer. While this is not as enticing as some of the earlier novels, Mayne is still able to keep the reader in the know and dazzle with his writing style!

Kudos, Mr. Mayne, for another great piece of writing!

Thank you to Netgalley, Thomas & Mercer and the author for an e-ARC of this novel.

This was my first Andrew Mayne novel and I really enjoyed it. I wish I had read earlier books in the series first because I feel like it may have given me a better connection to the main character earlier on but I was still able to enjoy the book regardless.

This one was a little slow to grab my attention but once it did, I was hooked and enjoyed the twist/surprise at the end which I didn't see coming. Giving this one 4 stars.

3.8 stars. Just another fun ride with Sloan McPherson and the defunct UIU. Andrew Mayne’s books have become delightful mind escapes for me. This wasn’t my favorite adventure but I still enjoyed it. I can’t wait until the next book and hope the UIU is fully resurrected. Thank you to Netgalley and the publisher for the ARC in exchange for my honest review.

I thoroughly enjoyed this book. I’ve loved the first three books in this series, so I knew I’d love this one. The fast-paced writing, the mystery, the character development, all kept me guessing through to the end. Sloan is still doing everything she can to solve any case she gets, regardless of the pushback from her superiors, and she gets the job done. I’m excited to see where Mayne takes Sloan and the UIU from here.

The whole reason to read this series is for the underwater element which is COMPLETELY missing from this installment. Also? The series is "Underwater Investigation Unit," and that unit does not exist for the entirety of this book... so it's a pretty standard cop drama starring a familiar lead who doesn't get to do anything she's good at or that we like to read her do. Silly.

The book was amazing!! Honestly couldn’t put it down at all. It had me on the edge of my seat the whole time and when it takes a twist you don’t see it coming and when you find out the truth in the end your mind is blown!! Thank you NetGalley for the ARC !

I really love this series. It’s just well plotted and thought out and a different take on the detective novel . The whole series is good.
Thanks to Netgalley and the publisher for letting me review the book

Sloan McPherson of the recently-dispersed Underwater Investigation Unit (UIU) is called in to investigate when the body of a young woman washes ashore in Fort Lauderdale. Local law enforcement seems eager to wrap up the case quickly, but Sloan is convinced that the young woman was the victim of foul play. Sloan soon finds herself teamed up with a bitter old Miami detective to solve the case as well as some old cold cases.

Although this is the fourth installment in the UIU series, it can easily be read as a stand-alone novel. Although Sloan’s old colleagues from the UIU are mostly absent here, she has met her match in Detective Gwen Wylder when it comes to circumventing authority and determination to solve crimes regardless of the danger or consequence. Sloan is a fantastic character, a strong female protagonist with a rebellious streak and a passion for bringing baddies to justice.

Sea Castle isn’t as action-packed as the previous installments in the series, but the plot was twisty and thrilling enough to hold my attention. Because the UIU has been sidelined, Sloan’s in/on water activities are mostly tangential to the storyline. I’m eagerly anticipating the UIU being reunited for more underwater adventures in the next installment!

Many thanks to NetGalley and Thomas & Mercer for providing me an advance copy of this book.

Sea Castle is the fourth in the Underwater Investigations series. This time, the UIU department has been temporarily disbanded. Sloan is sort of at loose ends before being paired with Gwen Wylder, a Miami homicide detective with a well earned reputation for being bitter, and maybe even a bit nuts. The two are investigating a current murder that maybe tied to others, suggesting a serial killer.
Gwen was an interesting character. Single minded, prickly and like a dog with a bone, hard to shake once she gets an idea. I missed Sloan’s old team. The plot here is slower and lacks the constant action of the prior three. It’s much more of a psychological thriller. It also takes place on land with only minimal time spent even near the water.
This time the real star of the book is the villain, who is a master manipulator.
The one fault I have with this series is that Sloan seems able to be the superwoman of sleuthing, finding obscure facts no one else can. It strains believability, but it didn’t affect my enjoyment.
My thanks to Netgalley and Thomas & Mercer for an advance copy of this book.

Loved this book!
Andrew Mayne always delivers on his books!

Loved seeing more of Sloan McPherson in action.
The twist at the end of this book was great and I absolutely loved it. Couldn’t recommend more.
This has become one of my favorite series!

This book is different from previous cause there isn’t the UIU team but they are mentioned and help at the end. I liked seeing Sloan handle things and come at different cases with different perspectives.

Thank you to NetGalley and Thomas Mercer for the ARC