They say every writer has a muse and mine is a black-and-white cat with long whiskers and an obsession with butter. We acquired Gus as a kitten sixteen years ago, a long time before the first Elly Griffiths book was published. Gus has been with me through the whole process: the early drafts, the rejections, the email from an agent saying the idea had ‘possibilities’, the thrilling moment when the first book appeared. Gus has seen it all.

 Gus is definitely the inspiration for Flint in the Dr Ruth Galloway novels. Like Flint, Gus has a cat flap but prefers personal service. Like Flint, Gus requires fresh food at each serving, watching intently as his repast is prepared, only to walk away when it’s presented to him. Like Flint, Gus sits in front of the television, fondly imagining that all eyes are fixed on him. And, though he’d hate to hear it, there are echoes of Gus in Clare’s dog Herbert in The Stranger Diaries and in Starsky, the German Shepherd in The Postscript Murders.

I work in a shed at the top of the garden. At eight a.m. every morning Gus makes his way to the door and waits for me. When it snowed recently, I followed his pawprints. He’s my furry writing conscience. He sits next to me while I write. He has his own chair but prefers to crouch by my computer. Occasionally he puts a fat paw on the keyboard and types a series of seemingly random letters and numbers. If only I could unlock the code.

When I do my morning yoga, Gus watches in disapproval from the top of the printer. He particularly hates Downward Facing Dog. When I’m teaching on Zoom, Gus waits his moment before inserting himself between me and the screen so that all my students see is black fur. If I’m immersed in work, Gus has a variety of strategies to attract attention. These include drinking loudly from my glass of water, standing on the shift key, pretending to be sick and Unearthly Yowling. This last is so disturbing that I’ve had neighbours calling round to ask if everything is all right, it’s just they heard this terrible, terrible noise….

 But, despite his many irritating habits, Gus is a great comfort to me. There is something about his solid presence that makes writing easier. He listens to my problems with plots and he’s understanding about deadlines. He’s also a great social media asset. I’ve learnt that a picture of my book gets maybe a hundred ‘likes’, but with Gus you can quadruple that number. He will even take part in the dreaded ‘unboxing video’ when the new hardbacks arrive. People often comment on how enthusiastic Gus is, how keen to see the latest publication, purring hopefully and even licking his lips in anticipation. It’s lucky that they can’t see the butter smeared along the edges of the box.

Elly Griffiths was born in London in 1963. Her first crime novel The Crossing Places is set on the Norfolk coast where she spent holidays as a child and where her aunt still lives. Her interest in archaeology comes from her husband, Andrew, who gave up his city job to retrain as an archaeologist. She lives in Brighton, on the south coast of England, with her husband, two children, and Gus.