Ruby and the Stone Age Diet is a classic Martin Millar novel with a jumble of sub-plots, twists and turns, and an unnamed narrator. Millar, once again, explores the world of Britain's underclass filled with dreamers, tweakers, and lovable misfits. Threads of storyline intermingle to create a literary fog that is great to get lost in.

Ruby says don't be silly and I say it is true and she says it is just the acid making me think funny things and I say what acid and she says the acid she put in my tea to make me feel better about Cis leaving me and after that I can't think of anything good to say.”
-pg 6

The overall plotline deals with the narrator's relationship with Ruby, his roommate and best friend. Both are confused about life, living as squatters, and can't decide whether to move on or stay with a love interest. Ruby is a hippie at heart. She goes around barefoot in a lilac dress, is on a Paleolithic diet, spends her time writing or painting, and talks about mythology constantly. Ruby's goal is survival, and in an off-beat way, she takes care of the narrator.

Cis is the sort of girl you see for five seconds in the street then think about once a week for the rest of your life.”
-pg 4

The narrator is just plain lost. Fresh off a break-up with Cis, he drifts from job to job, watches for a cactus to bloom, and has an odd relationship to outer-space robots. Whether the robots are an acid trip or just his dreams, it seems to be a good way to cope with poverty and heartbreak. Ruby's friendship saves him and, at the same time, keeps him from moving on. When she finally decides to take a chance on a real relationship with her on-again, off-again lover, it's just the right time for the narrator to finally figure out his life.

Millar is a poet and a realist. Ruby and the Stone Age Diet shows us a world as unsustainable as a diet where you never eat. The poet in Millar makes this bleak and hopeless world pop like Technicolor. What would seem to depress, instead uplifts and humors. Gods and Goddess of every known make fill this story, from “Helena, benevolent Goddess of Electric Guitarists” and “Daita, the Vietnamese Tree Goddess” to Alexander, who is “the God of Foolish People Who Walk Around Naked in the Hallway Thinking Their Lover is Shouting Through the Letterbox”. But they just can't compare to delightfully mundane scenes like buying a can-opener, because sometimes the simplest things, like best friends and cheap gadgets, make us the happiest. Millar proves, once again, that he hasn't lost his touch.