Charles winced, for he was watching a living memory of his own school days. Now a bell called the boys back into the building, two by two, and three by three, and Justin on his own.

Charles unfurled his umbrella against the hard drive of snow and stared at the park on the other side of the wide street. Mallory would be a straight shot across the park and a jog in the road north. Perhaps he would visit her if she was at the Rosens’ apartment. Also just the other side of the park was the crime scene.

Cabs passed by him, empty of passengers and ripe for the hailing, but he liked to walk in the snow. Over the years, he had acquired a taste for all the solitary occupations. And so would young Justin.

On his foul-weather meanderings closer to home, Charles would frequently encounter others in this select club. He was on a nodding acquaintance with fellow rain walkers and snow walkers, and they would smile at one another in passing, recognizing the secret sign – the gait of no pressing business, while all the other pedestrians were hurrying along, anxious to be out of the wet and the cold.

He crossed the street and took a path that wound down from the sidewalk and into a pristine valley of new snow. Only his footsteps marked the way until he came to the road which led through the park. He walked along the road, wondering what Mallory was up to, wondering if he would actually want to know that.

Now a horse-drawn carriage approached him. The snow ploffed on his umbrella, and it suddenly occurred to him that his shoes were not meant for snow. It crossed his mind to hail the carriage driver. But no. He let the carriage pass unhailed. New shoes could be got, new snow was not so easy to come by. He continued his solitary tracking.

What would Markowitz have said about Mallory’s negligence in failing to visit the crime scene? What might she have missed? Nothing, probably. Her refusal was most likely only an overreaction to Riker’s lecture on procedure.

Suppose he visited the scene himself, and possibly noticed something useful? How would she react to that? Well, they were partners, weren’t they?

‘You’re living in a fool’s paradise,’ said a voice which had come to shelter under Charles’s umbrella. ‘Behold a pale horse,’ said the man who materialized at his side to hold a conversation with a third person who was not visible to the naked mind.

Charles felt an involuntary shudder. He looked down to a shiny bald spot in the center of the smaller man’s matted swirls of gray hair. The old man’s coat was dirty, but good wool. A scarf was wrapped around his neck and trailed behind him on the ground. It was the longest scarf Charles had ever seen, and with all the colors of an unwashed, unkempt, unraveling rainbow. The man continued to walk along with him, accepting the shelter of the umbrella as though it were his due.

Charles knew he could never look on madness in the same way again. He had done his own time with one who was not there. And he had to wonder how often Malakhai had done that trick before the damage became permanent, before it became impossible to send Louisa away. Each thought changed the configurations of the very brain itself.

‘I am Alpha and Omega, the beginning and the ending.’

‘I’m Charles Butler. Good day.’ He moved the umbrella to one side, the better to protect his gray-haired companion from the driving snow which dusted the old man’s sloping shoulders.

‘And lo, there was a great earthquake; and the sun became black as sackcloth of hair,’ the old man intoned.

‘Well, perhaps it hasn’t been a good day,’ said Charles.

‘A woman clothed with the sun, and the moon at her feet.’

What is Mallory’s day like? What is she up to right now?

‘And there was war in heaven.’

That might not be far from the mark.

Now the old man parted company with Charles, as the invisible partner in conversation led the man down another path of revelation and gravel covered over with snow.

When Charles came to the site of the murder, the yellow strands of tape were still in evidence, stake-tied by their broken ends and waving in the white wind of snow.

He walked to the place confirmed by Heller’s map as the original murder scene. He stood by the water and looked around in all directions. So far he had learned nothing that Mallory might not have gleaned from the map. The site was within view of the path along the water. That fit nicely with Mallory’s theory of a spontaneous act. There was not sufficient cover to do a murder undisclosed.

The murder had taken place on a rainy day. Few people walked in the rain and the snow, but those who did were habitual in their defiance of the elements. He stared up at the towering building on Central Park West. The upper floors reached above the tree line of bare branches. Mallory might be looking out of one of those windows at this moment.

He walked around the leg of water to the path lined with benches, and then he sat down to wait. He had not been sitting there for very long before the one he waited on came walking along the path – the other walker in the snow.

He nearly missed her, though she was close. The bright snow had strained his eyes, and he had to work to pick out the particulars of her, the white face, white hair covered by the white woolen cape. She was as close to invisible as one could be without being a figment of the mind.

Cora pulled the hood of her white cape close about her face.

Too late.

He had seen through her camouflage. The man was very tall, but not threatening in his stance. She squinted to focus on his face which became clearer as he walked toward her.

Well, with that silly, wide grin, she might assume that he was one of the more docile lunatics who roamed the park at will. No, he was not dangerous.

Her hands went past the layers of sweaters beneath the white cape, and into the deep pockets of her white woolen trousers, looking there for a few coins.

‘Excuse me,’ the man said, standing before her now and bowing down to her so the wind wouldn’t take his words, and no matter if it did, for she read the words off his lips.

She drew the coins from her pockets and offered them to him. ‘Now promise me you won’t spend this on wine.’

‘Oh, no thank you. It’s not money I need.’

And now her suspicions were aroused anew. He didn’t want money? Well, he must be crazy, and perhaps dangerous as well. She turned away from him. He circled round to the opposite end of the path, but kept a courteous distance. There was an apology in the way he stood, and a foolish, hopeful look to his eyes, the pair of which had entirely too much white around the irises.

Oh yes, he was quite mad.

‘I need your help,’ he said. ‘It’s about what happened there on the morning of the nineteenth.’ He turned to point to that place across the dark water where the broken yellow tapes were waving in the wind. He turned back to face her before speaking again. He had already picked up on the fact that she was a lip-reader. That spoke well for presence of mind.

‘Ma’am, I don’t suppose you were out walking that morning?’

He seemed sane enough now. The shape of the words on his mouth had a good neighborhood to them, without slang or slur of form, and she could find no fault with his manners.

‘Yes, young man, I was out walking that morning.’

‘Did you happen to notice two people, a man and a woman, standing over there?’

He must be speaking of the young lovers, Blue Legs and the tall umbrella. Oddly, she felt protective of the young couple. Who was he to pry into their secret meeting?

‘Why do you ask?’

When he was done explaining that the lovers were murderer and victim, she felt the need to sit down. He sensed this and guided her to a bench a few feet up the path. He dusted it for her with touching chivalry and sat down beside her.