When I realised what was going on in Rebecca Hunt’s devastatingly good debut – I mean, I knew a bit from the hype and the cover, but when the whole dastardly idea enveloped me a few pages in – the feeling was one of utter delight. A horrified kind of delight, maybe, but delight all the same. The central conceit is that Winston Churchill’s depression, which he referred to as ‘the black dog’, is a rather foul individual called Mr Chartwell (Black Pat to his pals) who comes to visit. In this way, depression is presented not only as an illness but also, beautifully, as a character. A homewrecker. A sadist. A surprise. The book begins with Churchill waking to find the dog sitting in a chair in his bedroom, ‘a dark, mute bulk, watching him with tortured concentration’. Tortured concentration! I read that line and thought, YES. I’m in. Hit me with everything else you’ve got. And Rebecca Hunt did.

It’s a dark and creepy book, bristling with wit. It’s also a love story. Black Pat takes up residence in the spare room of Esther Hammerhans, a House of Commons library clerk who has advertised for a lodger. Grieving her dead husband, Esther finds herself equally intrigued and revolted by Black Pat, and increasingly emotionally involved. The dog – and the depression, it turns out – can belong to anyone. As he persecutes Churchill, his old spar, we fear for Esther, a sensitive, cardigan’d soul who seems no match for a shaggy mind-warlord. It’s compulsive reading. One of the things I love most about the novel are the descriptions of the dog as the physical embodiment of something irrefutable. This is a monster and no mistake. Over six feet tall, Black Pat walks menacingly (tauntingly, almost) on his hind legs. Black Pat is gross – distinctively doggy (sorry, I’m a cat person) – smelly and shameless. And, like all the best monsters, he has a caustic sense of humour. I imagine he was a lot of fun to write. That fun crackles off the page. Hunt writes with brio, the visceral often blooming into the mystical. Just before she opens the door to Black Pat, Esther can’t help but notice a particular odour, familiar on a species-level. ‘It smelt like an ancient thing that had been kept permanently damp; a smell of cave soil.’

I met Rebecca Hunt in a pub in London a few years ago. I was several sheets to the wind and fangirled at her for some time about how brilliant her book was. She took it like a champ. But despite my frothing, I meant every word. This is a lifer, a keeper; a book that sits, and stays, and charms, and changes. I am not the same person I was before I read it. If you haven’t already, I urge you to let it in.