He was at home in the city. Or he had been until the person he was stalking had taken the life of the last person on earth he loved.

The double glass doors of the building across the street opened and she walked out. Another woman, whom he had seen with her before, was at her side, as was a man in a shirt and tie. The women were carrying blue plastic kits that looked vaguely like fishing tackle boxes. The man was empty-handed, but the Stalker knew that tucked into a holster at the back of the man's belt was a pistol.

He got up from the table, folded the newspaper under his right arm and moved toward the door. He would make his notes in the book in his pocket as soon as he had time. He had filled eight identical books with notes. Those books sat in a neat pile in his dresser drawer, lined up chronologically. The first one began three months ago.

As he stepped into the morning heat and looked up at the sun, he felt a hint of satisfaction. The day would be hot, gritty. He would need a long shower and shampoo, but that would come later, much later.

Heat waves, like the one the city was presently going through, probably claimed more lives each year than floods, tornadoes and hurricanes combined. And the greatest human toll was in the cities, where the area of heat-absorbing dark roofs and pavements exceeds the area covered by cooling vegetation. Rural areas got some relief when temperatures dropped at night. The people of a city like New York were under further risk of health damage because of pre-existing stress on the body's respiratory and circulatory systems partly due to air pollution.

People were irritable, just as they had been in 1972 when New York suffered a two-week heat wave that claimed 891 lives. The Stalker had been here in 1972, but he did not remember suffering.