Henssen looked a little uncomfortable. "Well, Heini, I owe you something of an apology. I second-guessed you. The program allows parameters to be graded according to the confidence rating because there wasn't a shred of hard evidence to back it up; it was outweighed by other material. The same applied to the age factor. In neither case were we dealing with hard facts, only with guesses."
"Fair enough," said the Bear, "but I would like to have been told that at the time."
"The system is totally transparent to the user," said Henssen. "Any of the parameters can be looked at whenever you wish. After this I'll show you how it's done."
"Can we get back to the original topic?" said the Chief testily.
"Certainly," said Henssen. "Where was I?"
"Forward chaining," said Kersdorf.
"Ah," said Henssen. "Well, forward chaining is essentially a way of generating conclusions by applying rules, either formal or heuristic, to a given set of facts. If the bank customer pulls a gun and demands money and there is no suggestion that this is a security test, then a reasonable deduction is that he is a bank robber."
"And who said computers couldn’t think?" Charlie von Beck rolled his eyes. He was back in his bow tie and velvet suit.
Henssen ignored the interruption. "The point is, forward chaining is only one way to go about things. You can also use backward chaining. In that situation you could assume someone was a bank robber and then work back to see what facts supported that conclusion. It's an ideal way of checking out a suspect and ties in with the less rational elements of our human makeup, like intuition."
The Bear caught Fitzduane's eye and smiled.
"What it comes down to," the Chief said, "is that we have a much more flexible tool here than we seem to realize, and we're not using it to anywhere near its full potential. For instance, it can function in the abstract. Instead of asking, ‘Who do we have on file who has a knowledge of plastique?’ you can ask it, ‘What kind of person would have a knowledge of plastique, and where might he or she be found?’ The machine will then generate a profile based upon its file of data and its knowledge base." He rose to his feet. "Well, there you have it. Take of the blinkers. Try a little creative anarchy. Hit the problem from first principles. Find the fucking Hangman." After an angry look at everyone, he left the room.
* * * * *
Inspired by Katia, who believed that certain foods were good for certain parts of the anatomy, over the next three days the Bear ate a great deal of fish — a luxury in landlocked Switzerland — and, so to speak, kept himself to himself.
He wasn't so much antisocial as elusive. He went places and did things without saying exactly where or what. He made and received phone calls without comment. A series of packages arrived by courier and were unwrapped and examined only when he was alone. He was moderately talkative but only on any subject except the Hangman, and he was maddeningly cheerful.
On the morning of the fourth day Fitzduane, who had been researching variations of Swiss batzi with a little too much dedication the night before, rose at the unearthly hour the Swiss set aside for breakfast only to yawn to a halt in near-terminal shock at the sight of the Bear standing on his head, arms crossed, in the living room. His eyes were closed.
"Morning," said the Bear without stirring.
"Ugh," said Fitzduane. He turned on his heel and stood under a cold shower for five minutes. Toward the end he thought it might be a good idea to remove his robe and pajamas. When he returned to the living room, the apparition had vanished.
Over breakfast the Bear expounded on the merits of fish as a brain food. "Did you know," he said, "that the brain is essentially a fatty organ and one of its key ingredients, a free fatty acid, comes from fish?"
"Ugh," said Fitzduane, and spread butter and marmalade on his toast.
The Bear chewed enthusiastically on a raw carrot and wrinkled his nose at what Fitzduane was eating. "That's no way to start the day," he said. "I must get Katia to draw you up a diet sheet."
Fitzduane poured some batzi into his orange juice. He drank half the glass. "Ugh," he said.
* * * * *
Later that morning, after a detour to the Der Bund office to pick up a bulky file stuffed with press clippings, notes, and photographs, Fitzduane found himself trailing behind the apparently supercharged Bear as the detective hummed his way through the portals, halls, rooms, corridors, and miscellaneous annexes of the City of Bern art museum. The corridor they were in was in semidarkness. Fitzduane wondered about the wisdom of this policy. Perhaps visitors were supposed to rent flashlights. His mind went back to Kuno Gonschior's exhibition of a series of black rectangles in the Loeb Gallery. It had been the first time he had met Erika. It seemed lightyears ago. [(wtf?)]
The Bear stopped his march and scratched his head. "I think I'm lost."
The pause gave Fitzduane the chance to catch up. He leaned against the wall while the Bear consulted his notebook with the aid of a match. He was thinking that if the Bear continued in this hyperactive, hypercheerful mood, it might be a good idea to slip a downer into his morning orange juice before both of them had heart attacks.
There was a long, furious burst of what sounded like automatic weapons fire, and Fitzduane dived to the ground. The section of the wall against which he'd been leaning a split second before fell into the corridor, and a piercing white light shone through the gap in the wall. Fitzduane half expected the archangel Gabriel to make an appearance. Instead, a dust-covered figure clad in a zippered blue overall and carrying a heavy industrial hammer drill in both hands like a weapon climbed through the aperture, trailing cable behind him. He didn't appear to have wings. Head to one side, the figure surveyed the hole in the wall critically and then nodded his head in satisfaction, entirely oblivious of the 9 mm SIG automatic Fitzduane was aiming at his torso.
"Ha!" said the Bear triumphantly. "I wasn't lost after all." He looked down at Fitzduane. "Don't shoot him. This is Charlie von Beck's cousin Paulus, Paulus von Beck. He's a man of parts: the museum's expert in brush technique, a successful sculptor, and I don't know what else. He's also the reason we're here."
Fitzduane made his weapon safe and reholstered it. He still hadn't gotten his shotgun back, and it irked him. He rose to his feet, brushed dust from his clothes, and shook hands with von Beck. "Demolition or sculpture?" he asked. "Or were you just carried away screwing in a picture hook?"
* * * * *
Paulus left them in his office drinking coffee while he went to clean up before going to the restoration studios to examine the contents of the file the Bear had brought with him. When he returned, Paulus had discarded his sculptor image. The overalls had been replaced by a charcoal gray suit of Italian cut with creases so sharp it seemed clear that the art expert kept a steam press in his closet. His silk was hand-painted.
Paulus was older than his cousin. He had a high-browed, delicately featured face set off by a soft mane of wavy hair, and his eyes were a curious shade of violet. He looked troubled. Fitzduane had the feeling that the Bear might have stumbled across more than he'd bargained for. Paulus's demeanor was not that of a dispassionate expert; somehow he was a player.
"Sergeant Raufman, before I answer the questions you have put to me, I would be grateful if you would answer a few points I would like to raise. They are relevant, I assure you."