To recap: published in the US in 2001, Gob's Grief is the novel in which Chris Adrian  novelist, short story writer, paediatrician  sprang upon an unsuspecting world with his unique take on literary fiction. Adrian has since published two other novels: 2006's The Children's Hospital, about a floating hospital; and 2011's The Great Night, featuring Titania and Oberon living in San Francisco; as well as a short story collection, A Better Angel, which riffs off the characters and themes in his longer works.

All of these books have, during the course of the past year, been published in the UK, to be greeted with much the same acclaim as they received in the US. Hailed as a great innovator and inventor, Adrian has been the recipient of a Guggenheim and was one of the New Yorker's prestigious 2010 list of "20 under 40", which included Chimamanda Ngozi Adichie and Jonathan Safran Foer. So, Adrian is no longer an up-and-comer: he has upped and come. With the UK publication of Gob's Grief we are now able to go back to the beginning and see from whence it all upped and came.

From HP Lovecraft, mainly. Adrian combines elements of the supernatural, science fiction and horror that will be familiar to readers of Lovecraft's short stories, or indeed of Poe's, or MR James, or any of the other great 19th- and 20th-century prophets of non-realist, anti-realist, magical realist, weird, New Weird, slipstream, steam-punk, speculative, and otherwise bizarro fiction. Some will find these rich concoctions of genres and parts a profound, life-giving elixir, the very stuff of the imagination itself. Bring on the talking creatures, the derelict worlds, the crazy machines, the angels, the monsters and the sprites! Others will regard such stuff as nothing more than what one character in Gob's Grief calls "noxious effluvia".

It's both, of course. There are passages throughout Gob's Grief of shocking power: the strange story of the Urféist, for example, a child-eating beast who wears a kilt made of fingers and whose lairs are scenes both of abuse and revelation; and the ever-strange Pickie, a recurring character in Adrian's fiction who is the resurrected foetus/child of social reformer Henry Ward Beecher and his lover Elizabeth Tilton (the Beecher-Tilton adultery scandal was one of the most famous trials in 19thcentury America). There are also passages  300-odd pages into the novel, say  where the recounting of dreams, visions, nightmares and various spiritualist goings-on seem more for the author's benefit than the readers'.

The book is set during the American civil war. In an audacious prologue Adrian introduces a fascinating character, plucky young Tomo Woodhull, so plucky and so young, indeed, that the unsuspecting reader expects him to become the protagonist of the book. Tomo runs off to join the Union forces as a bugler, and is promptly killed. The action of the rest of the novel proceeds from Tomo's twin brother, Gob, attempting to atone for not having gone with him to war, and doing his utmost to bring him back to life. (In interviews, Adrian has explained that his own brother died in an car accident. The book is dedicated, simply, "For My Brother".)

Grieving Gob picks up some bits and pieces of occult, necromantic knowledge from the aforementioned Urféist, and then trains as a doctor in postbellum New York, where he befriends Will Fie, a fellow student who has also lost his brother, and who is tormented by various spirit beings. Clear so far? Gob then marries Maci Trufant, a journalist also grieving for the death of her brother, who continues to communicate with the world by using Maci's left hand. With these three weird brother-widows all assembled, the stage is set for the novel's climax.

There are also cameo appearances by Abraham Lincoln, early American feminist campaigner Victoria Woodhull and, crucially, Walt Whitman, who unwittingly finds himself at the literal and metaphorical centre of Gob's plans to make a machine to bring the dead back to life. This machine  a "great nonsensical conglomeration of mechanical parts that sat under an enormous telescopic gaselier whose fittings were cast in the shape of birds that shot flame out of their beaks"  Gob calls the "Kosmos", and Whitman becomes in effect the human battery powering this vast tangle of copper pipes, human bones, grief, compassion and loss. (Whitman's poem "Kosmos", keen students will recall, is a hymn to the universe in all its strangeness and amplitude.)

Weird vignette follows bravura passage follows profound musing, in what amounts not so much to a novel as a sheer outpouring of writing, an overflow of history, fantasy and fiction. Whitman, at one point, visits a makeshift hospital for the Union soldiers: "He took a walk around the building, gathering his courage and found a pile of amputated limbs, arms and legs of varying lengths, all black and blue and rotten in the chill ... He circled the heap, thinking he must recognise his brother's hand if he saw it." Just so Adrian himself circles, trying to piece together and to make sense of the world's grief and destruction.

 Ian Sansom's Paper: An Elegy is published by Fourth Estate.