Adam Nevill’s riveting ninth novel, Under a Watchful Eye (Pan, £12.99), ventures into the heartland of British horror so successfully charted by the likes of MR James and Arthur Machen. Horror writer Seb Logan is struggling with his latest novel when he becomes reacquainted with his old university friend Ewan Alexander, now a shambling down-and-out alcoholic who stalks and then moves in with Logan. Alexander is obsessed with the work of the horror writer and con man ML Hazzard, leader of a mystical cult investigating astral travel who, through Alexander, wishes Logan to do his bidding. Nevill charts Logan’s descent into the eldritch realm surrounding Hazzard and his cult with subtlety, drip-feeding doses of horror to great effect, ramping up the tension to an edge-of-the-seat denouement. You don’t read an Adam Nevill horror novel: you live it.

The Core of the Sun (Grove, £12.99) by Finnish author Johanna Sinisalo, translated by Lola Rogers, tells the story of the Eusistocratic Republic of Finland. This is a near-future dystopia in which women have been genetically altered to form two subspecies: eloi femiwomen, attractive and destined for procreation; and the intellectually superior morlocks, who are sterilised and consigned to lives of hard labour. Vanna is a morlock who passes as an eloi, searching for her lost twin sister who she suspects was murdered; in her grief, Vanna becomes a drug addict and a dealer. Through flashbacks, letters and sections from textbooks, the novel describes how the society developed. The Core of the Sun has been compared to Atwood and Vonnegut, but Sinisalo’s disturbing and often whimsical vision is uniquely her own.

James Lovegrove’s latest fantastical Holmes adventure, Sherlock Holmes and the Shadwell Shadows (Titan, £12.99), contains a conceit within a conceit. A preface by the author claims the manuscript was sent to him by a lawyer in Providence, Rhode Island, while Dr Watson’s introduction states that what follows is the true account of the exploits of Sherlock Holmes, and that the established canon has been adulterated to save the world from the terrible truth of the Cthulhu mythos. It’s a clever metafictional nesting technique which allows Lovegrove to mash together Doyle and HP Lovecraft to great effect. The year is 1880. Emaciated corpses have been turning up in Shadwell, and Holmes and Dr Watson’s inquiries lead to an evil genius who is intent on bringing the Elder Gods to Earth to further his own ends. The pastiche is pitch-perfect; Lovegrove tells a thrilling tale and vividly renders the atmosphere of Victorian London.

The Iron Tactician (NewCon, £6.99) by Alastair Reynolds is his fourth novella featuring the free-wheeling Merlin and his sentient starship Tyrant. Merlin is vain, wise-cracking and sardonic, though his heart is in the right place, and he is on a quest to locate a superweapon which, he hopes, will aid humanity against the onslaught of the implacable aliens known as the Huskers. This adventure finds him embroiled in a war between humans in a far-flung binary star system, helping one side to retrieve the eponymous Iron Tactician, an advanced military AI that might bring an end to the centuries-long conflict. Reynolds excels at capturing hi-tech far futures, imbued with scientific exoticism and peopled by believable characters.

One of the many strengths of Vic James’s Gilded Cage (Pan, £7.99) is its depiction of institutionalised magic being used to rule contemporary Britain, which provides a familiar backdrop for a fantastical premise. Britain has been ruled for 300 years by the Equals, an aristocratic elite who have the “Skill”, or magical ability. The have-nots, those without magical powers, are forced to undergo a decade of indentured servitude to the aristocracy or serve their time labouring in the grim northern town of Millmoor. The novel follows a diverse cast of characters drawn from both the unSkilled and the Skilled to give a rounded picture of the privilege and terrible deprivation that exists in a divided country. Beautifully characterised and compellingly plotted, Gilded Cage is an impressive debut.

Another accomplished first novel is Defender (Headline, £12.99) by GX Todd. Seven years before the story opens, humanity began to hear mysterious Voices that turned citizens into homicidal maniacs and resulted in a global apocalypse. Those left alive now engage in a dog-eat-dog fight for survival in which loner Pilgrim teams up with orphan teenager Lacey on a 600-mile trek across a blitzed US to locate her sister. As well as having to evade and outsmart ravaging homicidal gangs, Pilgrim has his own problems, not least of which is the Voice in his head … Defender is lifted way above other novels in the over-subscribed post-apocalyptic subgenre by Todd’s sympathetic characterisation and superb pacing.

• Eric Brown’s latest novel is Jani and the Great Pursuit (Solaris).