The sergeant clambered up the slope from his investigation. "Shot at close range. His own gun was still tucked away. Was he working, Sam?"

"He was tailing a guy named Thursby."

"Who for?"

"You know I can't tell you that." He turned a shoulder to go.

The sergeant cleared his throat. "It's tough, him getting it like that. He had his faults, like all of us, but he must have had some good points, too."

"I guess so," Sam assented, in a tone devoid of meaning, and left the alley.

In his office after 2 a.m., feet propped on the desk, he considered the death of his partner and the missing client who had hired them the day before. She had already checked out of her hotel that night; he had swung by there on his way back from the alley. She was not answering the cell number she had left the day before when she hired the firm, telling Sam and his partner a patent concoction of lies about this Thursby. If he didn't find her soon, and the truth she had withheld, the cops would pin him for his partner's murder — or at the very least lock him away for obstructing their case.

Pulling a battered laptop from the drawer, he tapped into the wireless carrier's back network, using a code and password obtained through less than straightforward means. On his smartphone Bluetoothed to the laptop, he called Ms. Wonderly's number. Again no answer. Caller i.d. would have told her he was seeking her. But as he watched, the laptop's powerful software teased her phone's location out of the carrier's database.

Government agencies and police routinely tracked cell users' locations without a warrant or court oversight. Officials claimed probable cause was not needed to obtain call information. Challenges had faltered, and no one seemed to notice any more, or care much.

As with other police procedures, the technique got frequent play from bail bondsmen, repo agents, detectives, and others on the fringes of — and within — criminal activity. It was pretty much open season on cell-phone users.

Privacy, at least as far as location, no longer existed. And many activities could be deduced from one's location.

Most callers were ignorant of this — they certainly weren't warned when they purchased their contract, for the carriers packaged and resold their customers' locations as an important revenue driver — and those users who were aware presumably believed the advantages of location-based services outweighed the invasive aspects.

"To live outside the law, you must be honest," he hummed to himself. The Coronet Apartments on California. He grabbed his hat and went.