One Heart, Two Liars by Kate Mallinder

Callie finds a note while beach-cleaning…


Your heart was rotten, so I killed you.

Only your heart hasn’t stopped beating; it beats in someone else now.

But not for long.


It’s in a bottle that looks vaguely familiar. She’s curious, as her sister’s just had a heart transplant, but from Ryan, a boy who died in a car accident, not someone who was murdered. So the note can’t be talking about her, can it?

But when she discovers the bottle has been taken from the art room, and finds out Ryan wasn’t as loved as she’d thought, she realises the killer is in her school and her sister is in danger. She must uncover who killed Ryan before they harm her sister.

About the Author

While completing Bath Spa’s MA in Writing for Young People part-time, Kate has had two books published by Firefly Press: feel-good teen novels Summer of No Regrets (May 2019) and Asking for a Friend (June 2020). She is represented by Hannah Sheppard from DHH Literary Agency. Pre-pandemic, she enjoyed visiting primary and secondary schools, taking part in festivals, leading workshops and chairing panels. She lives near Ashby-de-la-Zouch with her family and is involved with running local youth activities for teenagers. She grew up in Solihull, went to college in Leeds and lived for a while near Halifax. Kate’s perfect day would be full of books, snacks and cups of tea: all within breathing distance of the sea, which she dreams one day to live near.

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One Heart, Two Liars by Kate Mallinder

Over the two years on the MA I experimented with different age ranges and story types, but it was only towards the end of the course that this story arrived as an insistent idea. My tutor CJ Skuse encouraged me to keep exploring it, despite being tight on time, and I’m so pleased I did.

One Heart, Two Liars is a YA psychological thriller following Callie and her sister Rachel, who has recently received a heart transplant, the donor rumoured to be a car accident victim from the year above. Callie finds a note which appears to say the donor was murdered, and the killer is annoyed his heart still beats, although now in Rachel. At first Callie dismisses the idea of someone wanting to harm Rachel, but things happen which mean she can no longer ignore the threat to her sister. But can someone she knows really have killed the most popular boy in school? Callie must uncover who it is before they get to her sister.

‘Effortlessly readable, propulsive and well-paced.’

What was your inspiration for this story?

As a reader, my happy place is YA fiction in all its forms, so it makes sense, when a thriller popped into my head, that it would be set in a high school. I enjoy playing with voice, and especially so with this story, as I got to inhabit the mind of a killer for some of the time. I took it as a good sign that I sometimes creeped myself out!

What was your most memorable moment on the MA?

It’s not so much of a moment as a feeling: the feeling of being immersed in children’s fiction. To be surrounded by such talented, focused people challenged me to aim higher, to experiment with language and to tell the stories that speak to me.

What is the most important thing you learned on the MA?

I’ve learned to tune into my gut instinct. I worked on various ideas during the course but the tingle came when I found a story I couldn’t not tell.

What’s your favourite part of the writing process?

I love editing. Drafting feels so messy and haphazard. With editing I’m back in control, shaping the characters and story in the way I want. It’s so satisfying to polish and polish.

What do you like doing when you’re not writing?

I read a lot, obviously, but I also run a youth club for teenagers. I feel like I ought to get myself a hobby, but with a busy family life, there doesn’t seem to be the time.

What is your top piece of advice for aspiring writers?

Never give up. Rest, recharge, take a break maybe, but always get back up again and keep going.

What was your favourite book as a child?

There were so many, but I loved Goodnight, Mister Tom. It was the first book that made me cry, the first time I realised that books could reach right inside your heart.

What place in fiction do you most want to visit?

After 2020 I would take almost anywhere! Maybe the banqueting hall in Hogwarts, as those feasts sound amazing, or maybe Nancy Drew’s America – always sunny, always in a convertible and always with a mystery to solve.