He had first theorized that the brain was something like a muscle; the more you flexed it, the better it worked. That seemed logical, and he carried that around a long time, even after he became a policeman. He had really wanted to become a detective and had studied hard to prepare for the detective's examination. When he took the examination, he remembered things he was surprised that he had ever learned. That tended to support the-brain-is-a-muscle theory, but he suspected that there was more to it than that.

He saw comptometers on various bureaucrats' desks, watched them in operation, and thought that possibly the brain was sort of a super comptometer, but that (and its predecessor, the abacus) seemed too crude and too slow for a good comparison.

Then came the computer. Not only did the computer never forget anything it was told, but it had the capability to sort through all the data it had been fed, and do so with the speed of light. The computer was a brain, he concluded. More accurately the brain was a computer, a supercomputer, better than anything at MIT, capable of sorting through vast amounts of data and coming up with the answer you were looking for.

Some of its capabilities vis-a-vis police work were immediately apparent. If you fed everyone's license-plate number into it, and the other data about a car, and queried the computer, it would obligingly come up with absolutely correct listings of addresses, names, makes, anything you wanted to know.

Jason Washington had gone to an electronics store and bought a simple computer and, instead of watching television, had learned to program it in BASIC. He had written a program that allowed him to balance his checkbook. There had been a difference of a couple of pennies between what his computer said he had in his account and what the bank's computer said he had. He went over his program and then challenged the bank, not caring about the three cents but curious why two computers would disagree. He didn't get anywhere with the First Philadelphia Savings Fund Society, but a long-haired kid at the electronics store, a fellow customer, had taught him about anomalies.

As the kid explained it, it was a freak, where sometimes two and two added up to four point one, because something in either the data or the equation wasn't quite right.

By then Jason had been a detective for a long time, was already working in Homicide, and had learned that when you were working a tough job, what you looked for was something that didn't add up. An anomaly. That had a more professional ring to it than "something smells."

And he had learned something else, and that was that the brain never stopped working. It was always going through its data bank if you let it, sifting and sifting and sifting, looking through its data for anomalies. And he had learned that sometimes he could, so to speak, turn the computer on. If he went to sleep thinking about a problem, sometimes, even frequently, the brain would go on searching the data bank while he was asleep. When he woke up, rarely was there the solution to the problem. Far more often there was another question. There was no answer, the brain seemed to announce, because something is either missing or wrong. Then, wide awake, all you had to do was think about that and try to determine what was missing and/or what was wrong.

Jason Washington had gone to sleep watching the NBC evening news on television while he was going over in his mind the sequence of events leading to the death, at the hands of person or persons unknown, of Anthony J. DeZego.

Mr. DeZego had spent the day at work, at Gulf Seafood Transport, 2184 Delaware Avenue, which fact was substantiated not only by his brother-in-law, Mr. Salvatore B. Mariano, another guinea gangster scumbag, but by four of his coworkers whom Jason Washington believed were telling the truth.

Mr. DeZego had then driven to the Warwick Hotel in downtown Philadelphia in his nearly new Cadillac. That fact was substantiated by the doorman, whom Washington believed, who said that Mr. DeZego had handed him a ten spot and told him to take care of the car. The car had then been parked in the Penn Services Parking Garage, fourth floor, by Lewis T. Oppen, Jr., a bellboy, who had done the car parking, left the parking stub, as directed, on the dashboard, and then delivered the keys to Mr. DeZego in the hotel cocktail lounge.

Mr. DeZego had later walked to the Penn Services Parking Garage and gone to the roof, where someone had blown the top of his head off, before or after popping Miss Penelope Detweiler, who had more than likely gone there to meet Mr. DeZego.

There was additional confirmation of this sequence of events by Sergeant Dolan and Officer What's-his-name of Narcotics, who had staked out the Warwick. They even had photographs of Mr. DeZego arriving at the Warwick, in the bar at the Warwick, and walking to, and into, the Penn Services Parking Garage.

Mr. DeZego's car had been driven by somebody to the airport. Probably by the doer. Doers. Why?

"Wake up, Jason, dammit!" Mrs. Martha Washington had interrupted the data-sorting function of his subconscious brain. "You toss and turn all night if I let you sleep in that chair!"

"You act like I've done something wrong," Jason said indignantly.

His brain said, There is an anomaly in what Dolan told me.

"Run around the room or something," Martha Washington said. "Just don't lay there like a beached whale. When you snore, you sound like-I don't know what."

Jason went into the kitchen.

I will just go see Sergeant Dolan in the morning. But I can't take the kid with me. Dolan thinks Matt is dealing coke.

He poured coffee in a mug, then dialed Matt's number and told his answering machine not to meet him at the Roundhouse but to go to Bustleton and Bowler instead.

At nine-fifteen he went to bed, at the somewhat pointed suggestion of his wife.

He went to sleep feeding questions to the computer.

Where is the anomaly? I know it's there.

Officers Jesus Martinez and Charles McFadden, in uniform, came to their feet when Captain David Pekach walked into the building at Bustleton and Bowler.

"Good morning," Pekach said.

"Sir, can we talk to you?" McFadden asked.

I know what that's about, I'll bet, Pekach thought. They were not thrilled by their twelve-hour tour yesterday riding up and down the Schuylkill Expressway. They want to do something important, be real cops, and they do not think handing out speeding tickets meets that criteria.

Then he had an unpleasant thought: Do they think that because they caught me speeding, they have an edge?

"Is this important?" he asked somewhat coldly.

"I don't know," McFadden said. "Maybe not."

"Have you spoken to your sergeant about it?"

"We'd really like to talk to you, sir," Jesus Martinez said.

Pekach resisted the urge to tell them to go through their sergeant. They were good cops. They had done a good job for him. He owed them that much.

"I've got to see the inspector," he said. "Hang around, if you like. If I can find a minute, we'll talk."

"Yes, sir," Martinez said.

"Thank you," McFadden said.

Pekach walked to Peter Wohl's door. It was open, and Wohl saw him and waved him in.

"Good morning, Inspector," Pekach said.

"That's open to debate," Wohl said. "Have I ever told you the distilled essence of my police experience, Dave? Never drink with cops."

"You've been drinking with cops?"

"Two cops. My father and Payne."

Pekach chuckled. "What's that, the odd couple?"

"I went to cry on the old man's shoulder, and that led us first to Groverman's Bar and then to my place, and then Payne showed up to cry on my shoulder. I sent the old man home with Sergeant Henderson and made Payne sleep on my couch."