4.5/5The Reynolds are a very special family. Why did I not see this before? Silas in Sisters Red, Samuel in Sweetly, and now Celia, Anna and Jane in Fathomless. My mind is blown.Fathomless is a completely different beast from the other two books in this series, I almost don't know what to make of it. It's still spine-tingling and haunting, but it takes the fairy-tale retelling to a new level. I really like what Pearce did has done with the tale of The Little Mermaid - modernising it but taking it back to its gothic roots.Set in the same world as the previous two books, Fathomless features two three main protagonists - Celia, who doesn't fit in with her sisters, the third wheel to their twins; Lo, a mermaid who feels increasingly stifled with her life under the sea; and I can't tell you about the third for fear of spoiling you. Suffice to say, the predictions I made whilst reading Sweetly bore fruit. Lo jumps off the page - I can't believe how real she feels. I looked forward to all her chapters, her tortured experience of living in the darkness moved me, and my heart broke for her when it came to Jude. On the other hand, Celia initially felt boring. I think this is intentional on the author's part: Celia feels like she's a part of a set, and it takes her a long time to figure out an identity beyond that. Celia grew on me the more she grew into herself, and by the end of the book I respected and liked her.Unfortunately, the rest of the characters are a bit of a blur to me: Celia's sisters came off as selfish and controlling, and I ended up vehemently disliking them, Jude is kind of flat, with no real distinguishing features, and the other mermaids were mystifying (although I did like Molly).As usual, I'm left a little speechless at the world that Pearce has created, especially Lo's world in the murky depths of the sea. I also like her interpretation of mermaids, a far cry from Disney's Ariel. The world of the triplets is a little harder to immerse oneself in, a boarding school and small fair that didn't really resonate with me, but the ocean provides some balance.Like the other books in the series, Fathomless has a central focus in family, and sisterhood is deeply explored in this book. Not only does Celia struggle with her family and the obligation she feels to her sisters because of their powers, Lo feels a deep loyalty to her sister mermaids and it's difficult for her to leave the safety of her newfound family. The parallels between the two are clear - they both need to figure out who they are without their sisters.Another instalment of the gorgeous fairytale retellings is over, and I can't wait to read Cold Spell (based on Hans Christian Andersen’s The Snow Queen). I think fans of fairytales and good, dark fantasy will love this series by Jackson Pearce, and fans of Sisters Red and Sweetly are sure to enjoy this novel.You can read more of my reviews at Speculating on SpecFic.