Set during the English Civil War, Frances Hardinge's A Skinful of Shadows is the tale of a 15-year-old girl with a dark and supernatural family secret that she's desperate to escape from. We asked Frances what inspired the characters in her new novel, and what the heroines in her books all have in common.

What was it like writing a new book in the wake of your Costa win?

Winning the Costa Book of the Year for The Lie Tree was one of the most incredible moments of my life, and to be perfectly honest I'm still staggered by it. It did also up the stakes and increase the pressure! This was a bit daunting, and made it harder to write A Skinful of Shadows

What was your inspiration for writing A Skinful of Shadows?

My inspiration for a book seldom comes from a single place. Little idea-fragments grow in unattended parts of my brain, like dust bunnies, and eventually combine, like larger and more worrying dust bunnies. Bear came first. Hearing how badly dancing bears were treated, I imagined one returning as an angry ghost, unshackled at last and ready for revenge. The secrets of the mysterious Fellmotte family owed something to the film The Haunted Palace, one of the first horror movies I saw in my early teens. 

Were you inspired by anyone to write the character of Makepeace, either real or fictional?

My heroine Makepeace is not based on a real historical character, and actually it was a while before I properly understood her. Some characters are slippery like eels, and it takes time before I can get a grip on them. Those are the figures that interest me, though - the elusive, shadowy ones with hidden depths... 

Why did you pick a bear to star in this story alongside Makepeace?

My heroine's closest ally and confidant is a spectral bear. I liked the idea of a lowly, overlooked kitchen girl secretly playing host to a huge, angry predator. In some ways, Bear represents Makepeace's hidden anger and unruly feelings. 

What was it that most interested you about the historical period in which the book is set?

I'm fascinated by the English Civil War for so many reasons. I like periods of change, and at that time there was a sense that everyone had run off the edge of the world that they knew and were now in freefall. None of the old rules seemed to work any more. In fact, a lot of people thought that the world was about to end.

And in that chaos, lots of interesting people suddenly found a role for themselves. Idealists with startlingly modern ideas about equality suddenly came out of the woodwork. Quite a few women chucked aside their 'wife and mother' roles, and threw themselves into action with daring and cunning - defending castles, spying, smuggling gold and letters, setting themselves up as prophets, protesting, and even disguising themselves as men so as to fight in the armies.

Then there's the mixture of superstition and scientific zeal. A lot of people still believed that toads had jewels in their heads, that elephants had no joints, and that a man could be struck dumb if a wolf saw him. Educated men like Sir Thomas Browne were challenging all of these beliefs, in a sensible, scientific way... but still completely believed in witches.

Do you feel there is something that all the heroines of your book have in common?

My main characters (male and female) are different from each other in a lot of ways, but they do tend to have certain things in common. They're nearly always smart. They're usually angrier than anybody realises, including themselves. They're also frequently underestimated. This is always a mistake. 

Artist and illustrator Rachel, a.k.a. Aitch, shares how she designed the stunning jacket for A Skinful of Shadows. You can follow her on Instagram