The windswept mystery that brings the Wild Isle series to a powerful, poignant close.
There’s a strange sadness when reaching the end of a beloved series. I opened The Midnight Secret with both excitement and apprehension—ready for answers, but reluctant to say goodbye to Effie, Flora, Mhairi, and now Jayne. Thankfully, Karen Swan delivers a final instalment that’s as compelling and immersive as the books that came before it, wrapping up this sweeping historical mystery with heart, urgency, and grace.
Plot Summary
Set in the aftermath of the St Kilda evacuation, the novel follows the intertwined fates of the women we’ve come to know so well. While previous instalments focused individually on Effie, Flora, and Mhairi, this time we get alternating chapters from each of them—as well as Jayne, whose story finally takes centre stage. Jayne has always stood slightly to the side of the central drama: quiet, gentle, and seemingly passive. But in this book, we discover her inner strength as she endures a brutal marriage, hides a terrible gift—second sight—and ultimately holds the key to solving a long-buried murder.
Meanwhile, each of the other women face escalating trials: Effie’s engagement crumbles as she questions her place in a world of aristocratic expectation; Mhairi is ostracised and terrified for her unborn child; and Flora races across the Atlantic in search of the baby she surrendered in grief. Beneath it all lies the question that’s haunted readers since book one: who killed Frank Matheson?
Themes
Swan continues to explore themes of resilience, secrecy, and transformation. This final book is particularly focused on justice—both personal and collective. Jayne’s storyline touches on domestic abuse and the isolating power of shame, while Effie, Flora, and Mhairi each face their own reckonings. There’s a powerful undercurrent of female strength through solidarity; despite personal traumas, their loyalty to one another remains unbreakable.
And as always, the landscape looms large. St Kilda isn’t just a setting—it’s a living presence in the series. Even in their absence, the island shapes each woman’s choices, memories, and identity.
What Worked
What Worked- The interwoven structure kept me fully engaged. Alternating between perspectives felt natural and urgent, with no thread feeling neglected.
- Jayne’s emotional arc was heart-wrenching and necessary. I was surprised by how much I grew to care for her, especially after seeing her mostly in the background previously.
- The resolution of the murder mystery was satisfying and just the right amount of surprising. I didn’t see it coming—and I loved that.
- The rich atmospheric writing brought me straight back to the cliffs, the salt-slick rocks, and the howling winds. Swan’s prose made the island feel like home all over again.
Who Might Enjoy This Book
Anyone who enjoys historical fiction with layered female protagonists, slow-burn suspense, and sweeping emotional journeys will find this book deeply rewarding. It’s ideal for readers of Lucinda Riley or Susanna Kearsley, and absolutely essential for those who’ve followed the Wild Isle series from the start.
Conclusion
ConclusionThe Midnight Secret is an emotionally satisfying, beautifully told finale that ties up loose ends without losing the raw, lived-in feel that made this series so special. I will miss these characters—their strength, their flaws, their stubborn hope. But I leave them with a sense of peace, as though I’ve watched the tide carry them safely to shore.
Karen Swan, once again, proves herself a master of place, emotion, and story. If you haven’t ventured to St Kilda yet, consider this your invitation. You won’t want to leave.
Thank you to Pan MacMillan SA for the opportunity to read this book.
The other books in the series:
The Last Summer (The Wild Isle Series #1) by Karen Swan
The Stolen Hours (The Wild Isle Series #2) by Karen Swan
The Lost Lover (The Wild Isle Series #3) by Karen Swan
