Strange doings are afoot in the world of American high school series fiction, once all sleepover scandal and prom queen skulduggery. Among fans of cult TV, Sunnydale High is more famous than Hogwarts.

Sunnydale is the average fictional well-heeled small town in California with a mall, a drive-in and a population of gilded WASP youth. But the high school is also the site of the mouth of Hell, so vampires, zombies and the like abound.

Student Buffy Ann Summers has the ability to see off the evil beings, helped by a supply of handbag-sized stakes and her watcher (a mentortrainer called Giles who doubles as the school librarian).

Her cohorts include boyfriend Angel (who used to be a vampire and has several Pocket Book titles devoted to him) brainy friend Willow, spoilt mall princess Cordelia and Willow’s boyfriend, Oz, who is sometimes a werewolf and also (even more frightening) plays in a band. Hence the Buffy the Vampire Slayer TV series, which has an obsessive following among young teenagers, and its publishing spin-offs: novelisations and, more recently, graphic novels.

There are more than 20 novelisations, of which Deep Water is a recent example. In general in the series, dialogue, pace and characterisation is as sharp as in the TV scripts, but the descriptive writing that’s unnecessary in a script suffers by comparison. The plot of Deep Water looks beyond the standard Sunnydale choice of Gothic villains, borrowing from the myths of the selkie and the merrow, sea creatures that are about as Californian as North Sea herring.

The books have an addictive pulp fiction quality and a stronger narrative base than many horror series. You can read three at a sitting before the creaks in the prose make your hair stand on end.

Meanwhile the Buffy graphic novels that are relatively new to the UK (only four available so far) capture more of the flavour of the TV show while adding their own creative dimension.

Writer Brereton and graphic rtists Gomez and Florea tackle three slick, souped-up stories in Uninvited Guests - see also The Dust Waltz, starring the mother of all vampires, Lilith, by the same team.

Francine Pascal, creator of Sweet Valley High, has moved into Greenwich Village, a much tougher neighbourhood, with her Fearless series. Her 17-year-old heroine, Gaia Moore, like Buffy, marshals unusual powers against a conspiracy of dark forces. Gaia was born without the fear gene and has no sense of self-limitation to hamper her martial arts prowess.

Kim Reynolds, Roehampton Institute’s professor of children’s literature, referred to the Buffy books in her recent Silver lecture on fantasy (part of which appears in the Books in Schools supplement in today’s TES). She believes anti-conspiracy sagas empower children (many of whom believe, often correctly, that adults have their own conspiracy). Gaia is another empowering heroine in the Buffy mould, but there are important differences.

While Buffy is taking on the underworld, Gaia is up against an ill-defined human threat associated with her absentee father’s mysterious anti-terrorism activities. Her opponents recruit heavies from New York street gangs and plant spies closer to home.

Buffy complains that her Slayer tasks wreck her social life, but she has her loyal gang. Gaia feels isolated by her difference and her traumatic personal history, and alienated in her new school, although she builds relationships in the course of the three books (there are another six to come).

Pascal has created a complex heroine with more depth than her Sweet Valley characters, who faces meaty moral dilemmas.

These three titles are tightly paced and maintain interest with cliffhanger endings and clever typographic tricks. They seem shorter than they are (and they are already slender for the price).

Their content will force school librarians to hesitate before recommending them for under-16s, although younger teenage readers who want something with an urban edge might be drawn to them.

The Addams Family-style schlock in the Buffy books is one kind of scary - the real-life violence of Gaia’s encounters on the mean streets is quite another, and there is a disturbing psycho-sexual undercurrent to her dealings with her chief adversary.

GERALDINE BRENNAN