Child quickly establishes his happyish personality by intoning: “Someone needs to do bad before we can do good.” He cackles at the footpaths “leering at the kerbs”.

Hawthorn is a study of unease, prone to nightmares and a range of physical tics. Even sitting in the passenger seat appears to present a challenge to him. “He tried to manage his arms. They wanted to stretch but they were tensed up against the roll of the car. In his dream there had been ghosts as well, he thought ... Small dark ghosts with wings and muscles. Flapping. He became aware of a pain in his neck. And a headache.”

Within a few lines the gifted Keith Ridgway has created an exact place and positioned two vivid characters in it. From the opening exchanges between them, their partnership rings true. They are not caricature good cop bad cop. Everything about this vibrant, wonderfully written novel is alive, funny and deeply troubled.

Most of the characters are living, doing whatever it is they do, be it legal or illegal. One criminal seems to think he is God, while the young pickpocket working for him engages in bondage sex with his girlfriend. The couple express their feelings in a shared notebook; it’s easier to read. Love is difficult to speak about.

Poor Hawthorn, perpetually “filled with sorrow”, is struggling. Equally preoccupied is a book editor who may also be a killer. A minor but no less significant character gives up entirely in the most grotesque way.

The partners are on the trail of a crime lord named Mishazzo when a shooting occurs. It injects some urgency into the early morning. “Child punched the siren as they passed some taxis and a pedestrian crossing. He drove with his glasses slipped to the end of his nose and his head thrown back so that he could see through them.”

This incident ends in a hospital emergency room and the victim’s bedside, where “half a dozen people gathered around him with what you would swear was ill intent, such was the way they shouted and darted and snapped. They poked and peered at the body. They tubed the body and they hooked it up. They shifted and bound the body. They cut and pressed and injected the body. They worked on it as if furious.”

While this is happening the victim remains sufficiently conscious to answer questions from Hawthorn. A nurse’s hand appears to be holding his body together as he says: “A car. Shot me.”

It is brilliantly well done, as is everything in this muted technical tour de force. The young man, who may or may not be dying, seems hugely amused at the idea of being able to report: “A beautiful old car came out of nowhere and shot me.”

It is the randomness that makes this episodic yet cohesive narrative so effective. Ridgway conveys the way events are chaotic yet ordered, even connected. The writing is effortlessly lyrical, and Ridgway can venture into extraordinary, at times beautiful interludes of philosophical observation because his characterisation and, particularly, his feel for dialogue are so good.

It is a novel of contrasts: darkness and light. The daily and mundane balanced against the sheer hell of evil. One man, who is good with accounts, has secured an easy life - admittedly working for a gangster - but then he finds himself pinned under a car that could fall on him. Elsewhere a baby who is about to be rescued is thrown down a stairs. A woman who lives in a neat, spacious flat hangs herself over a cooker while the gas rings burn her from beneath.

In the midst of it all is Hawthorn, caught up in the gay sex scene and given to bursts of weeping. It is a world gone not so much crazy as menacing.

Ridgway, who was born in Dublin in 1965, has always been different, original and surprisingly undercelebrated. He impressed with his novella Horses (1997), which was followed within a year by his first novel, The Long Falling. His stories in Standard Time (2001) range from the very good to the excellent, while The Parts (2003), a multilayered comic thriller, took on Celtic tiger Dublin and left the city and the reader reeling. The novel casts a long, dark and compelling shadow, the influence of which echoes through Paul Murray’s Skippy Dies (2010).

The Parts begins: “Here we are. All mouth. All words and exhalations.”

Ridgway is a fearless though subtle confronter. He takes on the business of making sense of things. It is marvellously ironic that, having written that great Dublin novel, he has now written an edgy and profound London narrative, the type Martin Amis delivered in The Information (1995) yet failed to nail in the recent Lionel Asbo.

Where Ridgway succeeds time and again is that he never forces a joke or an image. It may seem vague and incidental, an ongoing crowd scene of a narrative, but then he cleverly tightens his hold. The young pickpocket out for a spree courtesy of some distracted football supporters is apprehended. “They were the worst kind of police. Suits. Relaxed. Blank-faced, youngish, stone-eared. They looked like estate agents ... It was Mishazzo they wanted ... They wanted a relationship. A friendly chat every now and again.”

It all goes back to the core values of Ridgway’s writing, the ease of his prose style, its fluidity and his mastery of characterisation and dialogue. Hawthorn is a most convincing figure, the Everyman at a loss. He is overwhelmed. Volumes are contained in a brief exchange between Hawthorn and his brother, a man with an everyday domestic existence.

“How’s the thing?” he asks.
“What thing?” replies Hawthorn.
“The crying,” explains the brother.

Things happen. Comments are made. There are encounters. But there is also a good deal of reflection. Some of the characters inhabit an interior world of thought, however confused. The young pickpocket says more to himself than he does to his boss, even when telling him that his abiding interest in life is himself.

Ridgway looks to the individual struggling and also explores a wider, beleaguered universe. As a character notes: “On the internet you can watch people dying, all over the place.”

After the horror, the violence and the chaos Hawthorn remarks: “Nothing ever happens to us, Child.” His partner replies, with deadpan irony dripping off the page: “No. Nothing ever does.”

The closing sequence, in which Hawthorn prepares with heartbreaking dignity a ritual breakfast for Child and his irritated consort, has a faint hint of events in another kitchen, in another Irish novel, a very famous one.

Read Hawthorn Child. Better still read it twice: it’s that real, that good, that true.