In spite of everything, I still love my husband… best not to see each other for a while… don’t want to hurt your feelings… you know how special you will always be to me… my duty is to remain with him.

He folded the pages with precision and placed them in a drawer. He had known Monica long before she had become the wife of a former murder suspect. She was an artist, stifled by a passionless academic husband, and yet she had returned to him. May’s vanity was dented. The women in his life had provided him with more heartache than any man deserved. His wife, his daughter and now Monica, all gone. Only his granddaughter April had been saved. She was working under his watchful eye at the unit, her agoraphobia held in check for the first time in years. The barriers between the pair had finally fallen, the circumstances surrounding her mother’s tragic death laid bare and forgiven. April was all he had left now. He would let nothing bad ever happen to her.

John May always felt old at the onset of winter. He was three years younger than his partner-and looked considerably more youthful-but his bones were just as tired. As the days grew shorter he questioned his motives for continuing. Suppose something happened to Bryant, as he knew it eventually would? Arthur veered between untapped reservoirs of strength and fault lines of frailty. How much longer could either of them draw enough stamina to continue fighting for the unit?

May grew annoyed with himself; self-doubt felt weak, but it expanded with age. The young were confident because they did not know any better. And for once it was he, and not Bryant, who needed a decent investigation in which to become absorbed. It was the best way to reconcile himself to the loss of such a wonderful woman.

As he shaved and dressed, he became more infuriated about the way in which the PCU was treated. The unit regularly suffered budget cuts and redundancies because it was a specialist investigation agency. As the nation converged on a single set of public services, the experts were being lost to countries that still held their seniors in high regard. He and Bryant were too old and too attached to London to ever consider leaving, and that made them obvious targets. After all this time the job should have got easier. Instead, they were now fighting for everything they had once been able to take for granted.

Our time must come, he told himself, although he had to admit that it was getting a little late.

The backlit fascia of the Mornington Crescent all-night taxi office bathed Detective Sergeant Janice Longbright in an unflattering shade of canary yellow. She shoved up the new roller-shutter covering the entrance of the Peculiar Crimes Unit and locked it in place with a strong right arm. The shutter had been added at the insistence of Raymond Land, after a gang of local thugs had rammed the door with a stolen builders’ van. Mornington Crescent, once an area of rough-edged gentility, of brown brick terraces bordered by damp green canals and soot-blackened railway lines, of dirt-grimed walls and windows and battered street signs, was becoming another London no-go zone of drunks and crazies, where keeping a watchful eye was no longer enough to protect you from harm. Figures for robbery, burglary, drug offences, fraud and theft were falling across the Western world, but here sexual attacks, acts of terrorism and brutal murders were on the rise. Small crimes could be thwarted by improved technology, but that left something stranger and more menacing on the streets. Bryant and May had insisted on staying at the epicentre of violent crime in the national capital, arguing-rightly, as it turned out-that they were as badly needed as any other emergency service.

The difference lay in the PCU’s operating methods. Unshackled from the endless backup procedures of the Metropolitan Police, they were able to occupy a unique place in the city’s investigative system. London remained a security nightmare despite its reliance on CCTV cameras, but the Met coped well with mopping blood, drying tears and calming fears; taking care of commonplace crimes was their job. Once, streets like Islington’s notorious Campbell Bunk had existed in gruelling poverty, beyond the boundaries of order and safety. Now, at least, the path was clear for specialist units like the PCU to investigate the misdemeanours that would have gone undiscovered in such areas.

Bryant told every prospective member of staff that their agenda knew no borders of class, age or race. Their remit was to settle sensitive cases with abstruse thinking, their purpose to prevent public panic and moral outrage. In recent years, the unit had become adept at handling the investigations the Met no longer had time to consider in depth. The Home Office now called the shots, and their demand for paperwork had increased until younger, more energetic staff were wasted in the daily untangling of office life that took place behind the crescent windows above the tube station.

As Longbright straightened her seamed nylons and gathered the weekend’s post from the mat, Crippen, the unit’s moth-eaten feline mascot, shot past her into the street, searching for somewhere to micturate. Arthur’s been to the office on a Sunday again and locked the cat in without putting its tray out, she thought. Doesn’t that man ever rest?

She clumped up the bowed stairs in her film-star heels, savouring the emptiness of the unit, wrinkling her nose at the smell of Bryant’s stale pipe tobacco. How long will the calm last this time? she wondered. Peace was both desired and dreaded, for although most of them welcomed a break from the long hours, it turned Bryant into a tyrant, as he stalked about the corridors getting on everyone’s nerves and under everyone’s feet.

That, she supposed ruefully, was the trouble with the Peculiar Crimes Unit; you never knew what you were about to get. Recently they had spent an unnerving week clambering about on the city’s rooftops looking for a man who called himself the Highwayman, only to discover that the unusual nature of his identity probably meant the guilty would never be properly punished. If anything, the Highwayman had become even more popular with teenagers in the weeks that followed his arrest. You still saw T-shirts bearing his logo on the market stalls of Camden Town. When ordinary people started glorifying cruelty and throwing rocks at the police, maybe it was time to find another job. Except that Longbright’s mother had worked at the unit before her, and had charged her with its protection. Janice felt possessive about the place, and knew that as long as she was needed here, she would face any challenge the detectives set her.

Sorting through the morning’s mail, she turned on the lights and began the day.

The winter sun seared the back of Madeline Gilby’s bare neck.

Only in the cafe’s shade were the chill tendrils of the season felt. She closed her book, pushed the blond fringe from her eyes and slid Euros across the palm of her hand, tipping them to the light in order to count them; the denominations were still confusing. The boy looked up at her anxiously from across the tiny wrought-iron table. Above them, swallows dropped to the eaves of the building, then looped out across the dark sea. Placing the money for the bill in the little white dish, she returned to her novel.

“Put the book down,” said Ryan. “You’re always reading.”

“You’ve got nothing to worry about, all right?” she said for the third time, setting the paperback aside. “We’ve enough to get by. I’ve told you, let me take care of the cash. You’re ten. You can start worrying properly in about eight years’ time, when we have to stump up for your student loan.”