Zohra Nabi introduces her first Cassia Thorne Mystery, Deep Dark

Deep Dark (Volume 1) (A Cassia Thorne Mystery)

About Author

Discover Deep Dark, the first adventure in Zohra Nabi's new Cassia Thorne Mystery series!

Zohra grew up inventing stories for her two younger sisters. She studied law at Cambridge and Oxford universities, but still secretly dreamed of being an author. Now she lives in London, browsing bookshops and writing magical adventures.

Interview

Zohra Nabi introduces her first Cassia Thorne Mystery, Deep Dark (Simon and Schuster)

March 2025

With its Dickensian setting and its exploration of greed and social injustice, Deep Dark brings to life nineteenth-century London through the adventures of 14-year-old Cassia Thorne, who is determined to discover why the city's children are going missing.

We asked author Zohra Nabi what inspired her first historical fiction novel, how she brings the past to life in her new mystery series, and what else she has planned for her young heroine, Cassia Thorne!

Review: "Deep Dark combines historical detail, fantasy and a sinister mystery to create a compelling adventure."

Read a Chapter from Deep Dark.

Q&A with Zohra Nabi introducing her Dickensian mystery, Deep Dark

"Dickens has shaped the way we experience London. It was enormous fun
to put my own twist on his work."

1. Thank you for joining us on ReadingZone! You're well known for writing children's fantasy (Kingdom Over the Sea). What has brought you into writing historical fiction for children with your new Cassia Thorne novels?

Thank you for having me! I always knew I wanted to set a novel in the past - I love history, and the fantasy world of The Kingdom over the Sea was hugely inspired by the history of the medieval Islamic world. I've also always really loved reading historical fiction and watching costume dramas, especially those set in and around London, where I've lived most of my life. It was a huge pleasure to pick a favourite era of history and try to bring it to life!

The biggest challenge was probably striking the balance between having enough historical detail for the world to feel rich and textured, without overloading the reader with facts. My editors gently reminded me that my audience are primary school-aged and not necessarily interested in reading about bonnets and mantles, or esoteric points about nineteenth-century company law… it was also an interesting challenge trying to make sure that Cassia felt like a relatable heroine to a modern audience.

2. What happens in Deep Dark, and what do you have planned for Cassia Thorne's further adventures?

So in Deep Dark we meet Cassia Thorne - almost 14 - living in the Fleet Prison with her father, a former merchant who lost everything when his ships sank. She's living something of a double life; she sells ballads at Bartholomew Fair and dreams of being a successful songwriter, but is also working for a wealthy family as a music teacher and hopes to move up in society. When Teo - a pickpocket and her source of sensational London stories - tells her that children are going missing, she reluctantly begins to investigate. So she discovers a conspiracy that goes right to the heart of the City of London, and to the Deep Dark below . . .

In the next book, Cassia faces a different challenge when she ends up in a boarding school in the north of England, where girls are wandering the moors at night, and there are rumours of witches lurking in the shadows….

3. What was the spark of inspiration for Deep Dark, a sweeping story about London City, monsters and disappearing children?

It's difficult to pick just one spark - there were so many that ended up coalescing in novel form! But perhaps a few stand out. First there were my legal history classes at university, which made me want to write a story in which we see the dramatic changes of the 19th century happening in real time.

There was also watching the BBC adaptation of Little Dorrit with my sister whilst she was revising for her university exams. It was a great reminder of how much I loved those stories, and gave me the idea of trying to write something set in a very Dickensian world, but that could nonetheless appeal to modern children.

As for the monster - I love old maps, which often depict sea monsters in the water. It felt like an interesting way of showing how crucial the seas were to the wealth of London at that time, whilst also adding an extra dimension of terror!

4. Deep Dark, A Cassia Thorne Mystery is a hugely atmospheric read. How did you go about absorbing 19th century London for this book? Did you do a lot of wandering around modern London?

There was a lot of wandering! I live fairly close to Farringdon, where Cassia Thorne is predominantly set, and I loved walking around and seeing all the remnants of old London which have been left behind from that era. There's even a grate in Clerkenwell where you can hear the river Fleet flowing underneath your feet…

The main research I did was academic research, with huge books I found second-hand, or by asking my sister very nicely to get out of her university library. One of the most interesting texts I read was Henry Mayhew's London Labour and the London Poor - you have to take it with a large pinch of salt, but even so the stories of life on the London streets were absolutely fascinating.

On the other hand, there were details I had accumulated over years which went into the book. Bartholomew Fair I knew about from being in a ballad opera when I was a child, and my memories of taking in part in that definitely influenced the book!

5. What are your writing tips for bringing the past to life, as you do in Deep Dark?

My main tip would be to think about how people are experiencing the world - what can they see, hear, smell and taste? Think about how the people living in the world have been shaped by their environment, how everything makes them feel, what they think about everything going on. If you have believable characters, we'll believe in the world that they're seeing.

Also, if you include historical detail, try to make it relevant to the plot - this is often a way of making your story more intricate too!

6. How much of your own cultural heritage do you bring to Deep Dark through Cassia Thorne's adventures, and how important is it to you as a writer to reference that?

It's an interesting question. Cassia and I have similar backgrounds, but very different experiences. On the one hand, she lived in Lucknow until she was eight, and unlike many Anglo Indian children of her time, had some experience of the incredible cultural life that existed there in the early nineteenth century. On the other, when we meet her she is living solely with her English father, attempting to pass as white, and she is very cut off from her culture and heritage. Consequently, I tried not to bring too much of my own experiences or culture to Cassia - although there are a few comments about her that I took from real life.

I think being mixed heritage myself naturally made me interested in the lives of mixed heritage individuals living in Britain at the time. How they navigated life, and what attitudes were towards them. The truth is, if we have historical fiction which features only white English people, we're painting an inaccurate picture of the past, which was populated by people of all backgrounds and nationalities.

7. At the heart of the novel is a monster that feeds on the blood of innocents while the City does its deals. Is it important for you to shine a light on social justice in your novels for children? Do you hope your readers will be encouraged to find out more, for example about the history of the East India Company?

Absolutely. I think a lot of the issues I write about in Deep Dark - poverty, homelessness, child exploitation - are still sadly very relevant today, and I think it's important to see them in books, and to see people try to make things better. I think by focusing these issues around a monster but showing real institutions interacting with them, they can be viewed both as the great evils of epic fantasy and as a part of our history.

It would be great if children wanted to look up things for themselves! That kind of reading is so fun I think, it's almost like detective work trying to piece together the past. Especially with the East India Company, which had such a profound impact on our society. Tracing links between past and present is so important, and so vital.

8. The novel also has a very Dickensian feel - and a heroine who shines a light on the poverty of the time. Are you deliberately referencing Dickens - and putting the pen into female hands?

The references to Dickens are deliberate, yes - it's a fun exercise to go through the book and see how many you can spot! I love those books so much, and Dickens has shaped the way we experience London. It was enormous fun to put my own twist on his work.

I wanted to situate Cassia in the tradition of many writers of the era, who used sentimental, cheap fiction to get across powerful ideas - there's an element of Dickens there, who published serials in popular magazines. But Cassia doesn't have the same respectability, and that's freeing for her even as it frustrates her ambitions of becoming someone important.

I think a lot of writers might relate to Cassia - I wanted to capture that mix of ambition and frustration and joy and frenzy that makes writing life so interesting to me. I definitely felt very close to her when I was writing Deep Dark.

9. Deep Dark is a fantastical and enjoyable adventure - but what kinds of discussions do you hope Cassia's adventures will encourage?

I hope it encourages discussion of the issues explored in the book around poverty, empire and exploitation - but also thoughts of how easy it is to forget about them, and to pretend the unjust things in the world aren't happening. I hope readers go away with a feeling that even though the world is full of terrible things and people, it is possible to stand up to them and to help change things for the better.

10. Who are your go-to children's writers, when you want to escape pen and paper, and what is your favourite destination to inspire your writing?

I love Eva Ibbotson's historical fiction, which is so gorgeously written and thoughtful - and I love the humour of authors like Joan Aiken and Terry Pratchett. There are a lot of brilliant contemporary children's authors I've enjoyed reading too - most recently I've loved the weird writing of Frances Hardinge, and the wonderful storytelling of Hiba Noor Khan.

My favourite destination for writing inspiration is actually Tate Britain - there's lots of nineteenth century art to look at and get inspiration from, and there's a really good café where I can drag a friend to come and write with me!

Zohra Nabi introduces her earlier fantasy, The City Beyond the Stars (Simon & Schuster)

In this sweeping fantasy adventure, The Kingdom Over the Sea and The City Beyond the Stars, travel through strange and magical landscapes with Yara and her friends as they seek to put right the wrongs of their society; to bring back the magic that has been lost to their world, and to help those who are in exile to return home.

Author Zohra Nabi introduces her magical fantasy, The City Beyond the Stars, which follows on from her debut, The Kingdom Over the Sea.

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