Or should he trust himself?

The Man who Turned into Himself is designed as a film noir of a novel, employing theatrical devices, quick-cut flicking between shots, and an evocation of the cult films and TV series of the Sixties. This should not be too surprising, as David Ambrose has made his career in theatre, television and film, and this is his first novel. Ambrose has a vivid visual imagination, and he writes as if he is sitting behind a camera, absorbed by the action in which he is involved at the same time.

The style is entirely appropriate to the subject. Rick Hamilton, a publishing entrepreneur, finds himself in what appears to be a parallel universe, inhabiting the brain of his alter-ego Richard, a respectable and stodgy estate agent. Rick's wife Anne is the funny, sexy partner; Richard's Anne is unfaithful in seedy motels, and cannot be trusted an inch. Rick and Anne are the loving couple, delighting in their child; Richard and Anne strive for the high life and the designer goods, and care very little for each other.

The contrast is neat enough for Ambrose to take it to Hollywood and say ‘look guys, I got this great idea'. it's made more dramatic by the introduction of a car crash, in which Rick's Anne seems to have been killed. It works by time-slips and flashbacks, and seems made for the cinema, a sort of Forward to the Past in the search for a point at which the film can be stopped and the future changed.

Yet Ambrose has deliberately invoked this familiar genre, and The Man who Turned into Himself is much more subtle than it first appears. It is, for a start, very sharply written, and the tendency to think in cinema cliché is presented as a possible delusion in the mind of an unreliable narrator. There is a sophistication and confidence in the writing which is very rare in a first novel, and a general sense of cohesion which rides over some occasionally — but only occasionally — repetitive phrasing.

Some of the most carefully crafted passages deal with the moments when the feelings are most raw, when the narrator is confronted by a trauma he cannot face, and begins to fear insanity. This is not just clever writing, but writing which questions the concept of cleverness. Ambrose takes contemporary sci-fi and pulls it off the shelves of the cranks. The plot is, to any rational mind, as improbable as religion, but it shares the same inexplicable sense of human aspiration.

The power of the novel comes from the internal voice of criticism which Rick represents in the mind of Richard, who is stuck in a dud job and a dud marriage and is driven to the point of violence. Rick, the intellectual, knows be is Richard's superior, and has to go quiet at times when Richard's emotions are out of control. It is a stunning study of schizophrenia, made more striking by the disturbing sense that these dual voices are not unrelated to the way we all behave under stress. The Man who Turned into Himself is not, at its heart, that far from The Ordeal of Gilbert Pinfold, and there is something of a similar tone of laughing despair and superiority over what is actually happening. There is also the same fear of madness and unwitting incarceration in echoes of the series The Prisoner.

I enjoyed and admired this novel, with its twists and turns, and its unexpected perspectives, which it would spoil a reader's pleasure to reveal. Ambrose juggles with many spheres: chaos theory, feminism, creative mathematics, friendship, love and jealousy. His first novel is a short work, which reads in the time it takes to watch a good film. It is well worth the money to spend an evening in.

A very contemporary publisher, Rick Hamilton, has a house in the country which costs rather more than he can afford, a little boy and a wife, Anne, who is pregnant again and with whom he is entirely happy. Rescuing the cat one morning he falls off the roof - not at all far and into a compost heap, so he only has a bruise or two.

But at a meeting that day he suddenly blacks out and wakes up to find he has become someone else - an estate agent called Richard Hamilton with a wife called Anne. A wife, moreover, who is two-timing him with Rick Hamilton's best friend, the lawyer Harold.

So far - and with a few phantasmagoric motor accidents thrown in - this sounds like the script of an ingenious and exceedingly gripping film. Indeed, David Ambrose is a successful director and playwright for international film and TV, who has now written his first novel. And like all good novels it goes on to do more, much more, than a film or TV play could do.

In one sense, it shows the mind involved in an endless and sinister conspiracy with itself - as if a self had been Jolted out of the usual habits and activities that make it one. Unemployed, it is engaged in a pointless and automatic effort to make a new self, in a way that dreams give something to do to a mind paralysed by sleep.

A part of the ordinary mind knows that it is employing itself in dreaming, but what if the dream is something we know to be true and our present self something imposed or made up? The novel gives a new and terrifying twist to the old platitude that delusion "is the patient's utter certainty that he is right and the rest of the world wrong". Sleep itself assumes a schizoid form. Rick/Richard grimly observes: "Richard sleeps - I don't". And the author too seems caught up in this identity confusion he studies so intently, dragging the reader in with him.

The confusion has some horribly homely features. Rick and Anne happily shared their fantasies when they made love. Richard finds himself engaging in them on his own and is aware that his wife is doing the same. Intimacy in bed can paradoxically produce a solitary self that didn't exist before: quite apart from the fact that one of you is having it off as another self with someone else.

The act of sex does Indeed present us with a self in its most ambiguous form and, while scrupulously avoiding the statutory bed detail of the contemporary novel, David Ambrose makes this clear, with that appearance of control and yet of bemusement which is one of the most remarkable features of a new and highly sophisticated fictional technique.

Surprise unobtrusively follows surprise in the course of his brief and tense narration. Will Richard actually see Rick, whom he is convinced he still is? He goes to his former house to find out and he meets somebody, but...Meanwhile he is in the hands of a blind psychiatrist, Emma Todd, who is brilliant and benevolent, and perhaps not even blind. (But what does her surname mean in German?)

Twists succeed twists and must not be revealed. I shall only say that the ending, eminently right and original as it is, has a touch both of Evelyn Waugh's Gilbert Pinfold and of the short stories of Ambrose Bierce.

This mesmerizing thriller will make you afraid to look in the mirror

In the middle of an important business meeting, Rick Hamilton, a Connecticut magazine publisher, receives a bizarre premonition: his wife is about to die. He rushes home to save her, only to find her dying in the middle of the road, her car crushed by a huge truck. He screams as the light goes out of her eyes, but then suddenly she is alive again, begging for help. Even stranger: she wears different clothes, calls him by the wrong name and denies that they have a son.

In The Man Who Turned Into Himself, award-winning screen writer David Ambrose has crafted a superb psychological thriller about loss, jealousy, deep terror and, most of all, identity. What would it be like to watch yourself from the outside, as an objective observer? When Rick finds himself inexplicably inside the head of his other-world counterpart, he has to figure out where he is and what's real. Yet this is only the first of the many delicious surprises that await Rick and the reader - brace yourself for three stunning twists in the last 20 pages!

The Man Who Turned Into Himself is, indeed, as our editor gushed, "unlike any other thriller I've read this year."