On the cover: a bright-eyed, tufty-eared dog sitting alongside a shiny-haired woman, her shaggy white coat echoing his. Dog and owner, equal companions in an urban café. In front of her: a full hangover breakfast and a plain mug of tea. Her eyes are humorous but sad. Hanging round her black polo neck is a smiley-face pendant, a tiny, druggy hint.

Meet Kate Spicer and Wolfy. Lost Dog is their story. She is a London journalist, well-connected but broke. He is a very special middle-aged lurcher, whom she finds, and loses.

That makes it sound as shallow as a Notting Hill airhead who writes up glitzy restaurant openings in between filling her nostrils with ’snowy-white toot’ provided by her Chelsea friend Timbo. This is Kate when we first meet her (in a dissolute late-night session that will make you snort with laughter). It’s a life she knows she must escape. From then on she is on a quest – not just to find a dog, but to achieve better balance in her life. With Wolfy at her side she meets mad cat-ladies, fashion PRs, yummy mummies and mastiff-owning bouncer-types, and draws an affectionate portrait of London at its best and worst, from pretentious parties to the sub-Westway traveller camp.

Wolfy brings her meaning and saves her from herself. Late one night, in a post-party taxi, her hand hovers over the number of her dealer, but the thought of her waiting hound takes her home to safety and the squeaks and cries of a grateful doggy friend.

Kate is frank about her struggles with her career, her finances and her love-life. Her hates are funny. There’s a great set-piece London dinner party, an arch-rival journalist she calls Melanie Oxbridge, and a successful Instagram-perfect babe she wonders if she should envy. But when Wolfy is lost, her desperate search through London’s green margins and grim housing estates takes us deeper into midnight doubts and glimpses of a messed-up childhood and a grandmother she mourns.

Wolfy is posited as her saviour but there is evidently another rescuer at work; writing. She captures it all with a self-mocking voice that can edge into despair. You know how Lost Dog ends, but she wraps you up and keeps you reading. And she can nail details: the molten Dali-esque sculptural sofa in a fashionista’s home, a mini-cab’s pod of body smells and Magic Tree fragrance, her nervous twisting of an old bone-shaped dog biscuit that she finds in her pocket as she makes the final discovery.

Fundamentally this book is about love and our place in the world. “You cannot rationalise love...it is our route to something beautiful, mysterious, and transcendent. Without it, life is a hollow set of functions and, frankly, fucking pointless.”

Lost Dog with Kate Spicer and Wolfy 8pm Thurs 25 April, The Theatre