Next week marks 20 years since the death of the Scottish novelist, short story writer, poet and essayist Muriel Spark. She was best known for her 22 novels – uncanny, astute and witty – beginning with her 1957 debut The Comforters. Here, James Bailey, the author of a new biography, Like a Cat Loves a Bird: The Nine Lives of Muriel Spark, guides us through her oeuvre.

The entry point

Allowing for exceptions, a Spark novel has a particular method of reeling us in. She starts by introducing an enclosed community (be it of nuns, schoolgirls, or desert island castaways), which is full of gossip, deceptions and conflicts both petty and profound. Into this little world she drops a bomb: murder, scandal … or an actual bomb, if she’s feeling particularly reckless. She stands well back, and lets us watch as sparks fly.

Anyone new to Spark’s way with a story would do well to start with 1959’s darkly comic Memento Mori. The novel introduces a cast of bickering pensioners, who find themselves troubled by anonymous phone calls. Each call contains an identical message: “Remember you must die.” Does death’s imminence liberate us from our fears, squabbles, jealousies and neuroses, or do these things cling to us like barnacles until the bitter end?

Early in 1954, 35-year-old Spark was hurtling towards a nervous breakdown. Hungry, poor and overwhelmed with work, she had begun using the stimulant dexedrine as a means of forgoing food and writing through the night. “It made you less hungry,” she later said of the drug, “but it also made you dotty.” She wasn’t kidding; under the influence, Spark came to believe that secret codes were hidden in the books she was reading, and that TS Eliot was spying on her while posing as a window cleaner.

Fortunately, she recovered from the ordeal, and put the experience to use in her extraordinary debut novel The Comforters. There it is her protagonist, a writer named Caroline Rose, who senses her grip on reality loosening. Caroline believes she can hear the clanking typewriter keys of an entity she calls the Typing Ghost, whose capricious imagination dictates the events of her life. She refuses to submit, however, and a tussle between character and author plays out in a book that features diabolism, diamond-smuggling, and characters so insubstantial that they occasionally vanish into thin air. “It is always a joyful thing when a novelist breaks the obvious rules of fiction and gets away with it,” Spark wrote in the Observer a year after its publication. She was just getting started.

The most quotable

“Give me a girl at an impressionable age and she is mine for life,” announces Jean Brodie to the six schoolgirls who make up her special “Brodie set”. Her declaration joins a host of other sayings, all spoken within the first few pages of Spark’s best-known novel, that sound as if they’ve been said countless times before: “I am in my prime”; “I am putting old heads on your young shoulders”; “All my pupils are the creme de la creme”. To be exposed to these lines is to be indoctrinated into the language of a secret society. It is to feel cocooned, privy and elect, as though you yourself are one of Brodie’s elite.

How skillfully Spark sets up The Prime of Miss Jean Brodie, her tale of favouritism, fascism and the seductive power of belonging. Suddenly, the world outside Brodie’s classroom seems a rather drab place to be. “You will end up as a Girl Guide leader in a suburb like Corstorphine,” she warns a girl who falls short of her expectations.

The masterpiece

The Driver’s Seat was the book Spark believed to be her finest achievement. Why? Because she also considered it her creepiest. I’m inclined to agree on both counts. Published in 1970, in the middle of a run of taut, elliptical works such as The Public Image and Not to Disturb, it reads like a holiday romance that has been disassembled and grotesquely rearranged. Its protagonist, Lise, is off on her travels in a nice new dress. She’s going to meet the man of her dreams, she remarks chirpily, before boarding her flight. You’ll have to brave this brittle little book to discover exactly what lurks in those dreams of hers, but be warned: the answer is more Shirley Jackson than Shirley Valentine.

The one about how we live now

Spark had a special knack for depicting life’s narcissists, self-mythologists and charlatans, and was fascinated by the contrast between a glittering public persona and the figure that stoops in its shadow. She’d have had a field day on social media.

We can learn a lot about our present moment from her 1968 novel, The Public Image, written in Rome during the rise of the paparazzi. The plot concerns a film star’s desperate attempts to salvage her reputation, after her similarly self-absorbed husband sets out to damage it beyond repair. In the process, our protagonist descends ever deeper into a world of artifice, losing all sense of who she is or ever was.

The ones that deserve more attention

“He looked as if he would murder me and he did.” Those are the words of Needle, the ghost who narrates the 1958 short story, The Portobello Road. Having found her voice, Needle has returned to tell her tale and prick the conscience of her killer. She is one of the many unquiet spirits who haunt the pages of Spark’s short fiction. These ghost tales, which make up a significant portion of her Complete Short Stories, deserve a closer look.

Many of Spark’s ghosts are extraordinary in their utter ordinariness. They ride the bus and maintain their rented rooms. They resurrect old feuds and embark on unwise affairs, and still visit their sweet old aunts at Christmas. Sometimes they visit their author, too. Harper and Wilton, the titular protagonists of an unremarkable short story Spark published in 1953, return from the dead in a revised version from 1996. They berate their maker, twisting her arm until she writes them a better ending. How creepy. How playful. How very Spark.