PHOTO: Author Hannah Mary McKinnon, photographed by her husband Robert McKinnon, brings thrilling emotional depth to both her suspense novels and romantic comedies.
Internationally Bestselling Author Balances Darkness Emotion And Wit
Internationally bestselling author Hannah Mary McKinnon opens up about her suspenseful thrillers, emotional character work, creative process, and her unexpected return to romantic comedy under the name Holly Cassidy.
Hannah Mary McKinnon has a rare gift for traversing the shadows of the human psyche while keeping one foot firmly planted in emotional truth. Born in the UK, raised in Switzerland, and now writing from Canada, McKinnon has carved out a distinctive voice in psychological suspense—one that refuses to sacrifice character for shock or plot for pulse. Whether she’s exploring fractured families, long-buried secrets, or the thin line between guilt and redemption, her work pulses with insight, wit, and unforgettable tension.
From the vengeful charm of Never Coming Home to the layered friendships in Only One Survives, her stories are grounded in people as flawed as they are fascinating. She doesn’t shy away from the darker corners of morality, often asking her readers to root for characters who are anything but conventional heroes. And yet, amid the grit and danger, there’s often a thread of humour—or even hope—that lingers.
Her newest novel, A Killer Motive, promises yet another descent into layered suspense. With a protagonist driven by grief and haunted by unanswered questions, McKinnon once again challenges the reader to ask: what would you do if you thought you finally had the chance to make things right?
Just as striking is her turn under the name Holly Cassidy, where she explores joy, love, and the sparkle of holiday romance. Whether writing thrillers that twist the knife or comedies that warm the heart, Hannah Mary McKinnon is—at her core—a storyteller of deep empathy and daring imagination.
McKinnon masterfully blends gripping suspense with emotional depth, creating unforgettable characters and stories that linger long after the final page.
In Only One Survives, how did you balance the raw emotion of female friendships with the suspenseful elements of a thriller?
It really comes down to a mixture of character development and pacing. As with all my novels, I spent a lot of time developing the Bittersweet band members, so I understood their backgrounds and emotions fully. I always “interview” my main characters, meaning I put them through a 3-page questionnaire. This allows me to get to know them and ensure they don’t all seem the same to me or the reader. Subsequently, I blended this character development with the suspenseful elements of the thriller, of course ensuring the twists and turns fit not only the plot, but also the characters I’d created.
What inspired the character of Lucas Forester in Never Coming Home, and how did you approach writing a likeable anti-hero?
I’m so glad you find Lucas likeable, too! Essentially, I wanted to write about someone who was evil, despicable, but also relatable and definitely funny—and whose enemies were even worse. Cue Lucas. Writing a whole novel from the antagonist’s point of view was an entirely new experience, and I loved it. I ensured Lucas was fully rounded, gave him a wicked sense of humour, and a deep love of his dad, and stray dog, Roger. Despite Lucas’s many flaws and murderous ways, I enjoyed spending time with him. He made me chuckle during the dark days of the pandemic, and I’ll forever be grateful for that.
“I always ‘interview’ my main characters so they feel fully real to me and to the reader.” – Hannah Mary McKinnon
The Christmas Wager marked your return to romantic comedy under the pseudonym Holly Cassidy; what prompted this genre shift?
It’s a bittersweet origin story. My mum passed away a couple of months after the pandemic hit, and I couldn’t get to Switzerland to say goodbye. It was one of the most gut-wrenching, guilt-inducing experiences of my life. During that time, I worked on Never Coming Home. Although it’s crime fiction, it turned out to be funny (dark and twisted humour, but humour nonetheless), and that happened because I needed to escape someplace where I could laugh when everything else felt so desperate.
I enjoyed writing the humour so much, I wondered if I could return to my romance roots (my first book, Time After Time, was a romance). I played around with a few ideas but didn’t do much with them until my agent asked if I’d thought about writing a romantic comedy. Now, that’s what I call serendipitous! The Christmas Wager and The Christmas Countdown were published in 2023 and 2024 respectively. It’s been a delight to explore the lighter side of life in between my murderous ways.
With A Killer Motive set to release in September 2025, can you share any insights into its themes or characters?
A Killer Motive is the story of Stella, a true crime podcast host whose teenage brother vanished six years prior from a beach party Stella took him to. When she’s on a radio show, promoting her podcast, A Killer Motive, she says that if she found just one clue about Max’s whereabouts, she’d find him and bring whoever hurt him to justice. Little does she know that someone who’s listening to her every word takes that as a challenge. A Killer Motive delves into lies, guilt, betrayal, redemption… and hopefully my most twisted and surprising antagonist yet.
“Lucas was evil and hilarious—and I loved writing every moment of his wicked story.” – Hannah Mary McKinnon
How did your transition from a career in recruitment to writing novels shape your storytelling approach?
In my corporate role, I often led different projects, e.g. building and implementing solid back-office policies and procedures from the ground up, opening subsidiaries in the Netherlands and Germany, leading due diligence for a company sale, or coordinating company mergers. I thrive being in new situations and figuring out how to work through them. This translates to my books as my new cast of characters is always in a brand-new scenario, and I have to help them get out of it (or not…). Whenever I don’t know something, I’ll find an expert who does. My organisational and networking skills also come in handy, as does my head for business to understand the publishing world.
Your thrillers are known for their unexpected twists; how do you craft these surprises to keep readers engaged?
Thank you, that’s a lovely compliment. Essentially, I break my story into small steps, from beginning to end. While I don’t come up with every single plot point or twist, I have the main beats, which help me move from one chapter to the next as I outline the book. When I draft and thereby further develop the story, I come up with more twists as I go along – sometimes even in the last pass right before I send the manuscript to my editor. I love that “Aha!” part of the writing experience – when I’m surprised, I hope my audience will be, too.
What key advice would you offer to aspiring authors aiming to write compelling psychological thrillers?
No matter what genre you’re writing, read as much and often as you can and listen to audiobooks. Pay attention to how the genre is structured, and when the main plot points and twists occur. Figure out what you like, and thereby what you’d like to read. Write, even if you think it’s terrible—you can’t edit an empty page. Another tip someone suggested was to skip ahead if I couldn’t figure out a chapter or scene, that I should focus on another part of the manuscript and trust myself enough to backfill later. It was revolutionary to think that although a book is read in a linear fashion, it doesn’t have to be written that way. Share your work. It can be scary, but it’s the only way you’ll get feedback and improve your craft. And finally, fully develop your characters. If they feel real to you, they’ll feel real to your readers.
“The humour in Never Coming Home helped me survive one of the hardest times of my life.” – Hannah Mary McKinnon
