Amita had been calling Charlie's cellphone and leaving voicemail messages for a day and a half. When she finally filled the voicemail box, she called Terry Lake instead. Terry gave her the party line: "the incident involving Dr. Eppes had nothing to do with his consulting work for this agency…Dr. Eppes is not a suspect…Dr. Eppes cooperated completely and the agency has released him to his own custody…." Even as she talked, Amita could hear Terry shutting off her computer, opening and closing drawers, finding keys. "I'm leaving the office now," Terry said at the end of her spiel, "I'll meet you at the hospital."

At Queen of Angels, the two women split up; Terry would sit in Don's room and Amita would wait in Alan's. Sooner or later, Charlie would appear. Amita hated just sitting, though, and she'd started pacing, first in the room, then in the hallways. It was a habit she'd picked up from Charlie. Before long, she ended up in the neonatal ward, a kind of hospital backwater that drained people away from the bustling main corridors. And she would have recognized those curls anywhere.

"Charlie!"

Her professor turned around and blinked, gave her a wan smile to show that everything was OK. Amita was not convinced: Charlie was wrecked with exhaustion. He was jumpy and unshaven; his hair stuck up at strange angles, even his eyelids looked raw from lack of sleep. When she reached suddenly to take his hand, Charlie was so startled that he pulled away and cracked his elbow against the big window behind him.

"Charlie, it's time to go home." Amita thought for a minute that he might refuse—then what would she do? The man was her thesis advisor, for God's sake, she couldn't very well force him!—but finally he nodded absently. He didn't seem to realize that she meant now, so she reached out, slowly this time, and took the corner of his t-shirt. By this slight leash, she led him out of the hospital and into her car. He waited while she called Terry, then obediently climbed into the passenger seat and let her help with the seatbelt. Normally sensitive about his personal space, Charlie didn't even seem to notice that she practically had to climb into his lap to adjust the seatbelt around his bandaged arm.

"Everyone at school is asking for you," Amita began when they'd pulled out into traffic, just to make conversation. "Carol is asking for you and Marianne is just beside herself, of course. She's the one who gave Anthony your address. She didn't know, of course…that it was going to happened, I mean, she just remembered that you're always willing to meet with students over the summer."

"Hmmm, that's nice of her to remember," Charlie said distantly, his eyes fixed on the freeway. Then, a few minutes later, "Who's Marianne?"

"The secretary, Charlie—the departmental secretary!"

"Oh, oh, right. Yeah. Well, not her fault, of course." He lapsed into silence.

"And Larry wants you to call him if you need anything at all." Amita began again, glancing at Charlie from the corner of her eye, trying to remember the rest of the physicist's jumbled message. "Oh, and he says don't forget, uhm,…Moritz Schlick?

Charlie smiled at that and Amita just had to ask: "Who is Moritz Schlick?"

"He's a physicist—was a physicist, I guess. He's dead now."

"Oh, I'm sorry!" Amita apologized automatically, wanting to bite her tongue, and that made Charlie look at her (finally!) and laugh. She was surprised at how glad she was to find out that his laugh hasn't changed at all.

"No, no, he's not a friend or anything," Charlie said, "The man's been dead for, like, seventy years. It's just another of Larry's Parables from the Lives of the Great Thinkers."

Amita nodded, keeping her eyes on the road, betting that Charlie won't be able to resist the teaching opportunity. She's right.

"Schlick was a student of Max Planck in Germany," Charlie started, "but he really made his mark as a professor at the University of Vienna. He led a famous philosophy discussion group." Charlie relaxed into his role as teacher, sitting up in his seat, turning to face Amita. A lot of smart people like to make the most of what they know, she thought; they like to flaunt their learning, letting others see but never touch. Charlie, on the other hand, is profligate with his knowledge: never happier than when giving it away. "There were a lot of discussion groups in Vienna at the time. The housing situation was terrible—and, you know, it gets cold, what with the Danube and all—so people spent most of their time in cafes, arguing over science and literature and architecture. But the Schlick group was known as the Vienna Circle because it was the most prestigious. And, while it's most famous for philosophy logical, many of the Circle's members were mathematicians, not philosophers. Kurt Godel was a member as an undergradate. John von Neumann used to drop in when he was in Vienna. Do you know the Hahn-Banach extension theorem?"

Amita dragged the name from the corner of her mind, "You mean, like, in functional analysis?"

"That's the one. The Hahn for whom it was named was a member of the Circle. So was his wife, for that matter—Olga Neurath. She was blind and smoked cigars and wrote a fascinating paper on the algebra of classes. Did I ever assign that? I should, she's brilliant. Neurath's stuff. Yeah…for the symbolic logic seminar."

Charlie was totally lost by then, in the numbers and the Vienna damp and the smoke from Olga's cigars. He knew everything about the coterie of a long-dead German philosopher but couldn't remember the secretary whom he greeted every day of his working life. Amita would have expected nothing less.

"And then…?" she asked.

Charlie seemed to deflate. "Well, then Schlick died and the Circle kind of fell apart."

"So?"

"So— " Charlie shrugged, "it's probably just as well. The Nazis were coming to power in Vienna and they didn't look kindly upon that kind of intellectual discussion."

"Charlie!" Amita rolled her eyes, "That's not what I meant."

"What did you mean?" He asked carefully, refusing to look at her, watching instead the familiar houses on his street.

Amita pulled into the driveway and parked her car but didn't unlock the doors. "I meant that Larry's stories usually have some relevance, however obscure. What's the rest of the story?"

Charlie untangled himself from his seatbelt and almost said that he didn't remember. Larry and his stupid morality tales! He was tired, his arm hurt, he didn't want to talk anymore. But Amita was a research whiz; she'd find out for herself and then she'd see more than was really there.

"The Circle dissolved when Schlick was shot and killed by one of his former students, a young man who blamed his professor for his inability to find a job. The student was, uhm, not well. Delusional. Twice he'd been committed to a psychiatric asylum for stalking Schlick. People said Schlick was too cavalier about it, that he knew this student was dangerous and didn't take sufficient precautions, preferred to believe that he was popular and beloved. The Nazis in power said that he was a godless Jew who got what he deserved." Charlie took a deep breath and unlocked his door. "Incidentally, Schlick was baptized Protestant, although he may indeed have been godless. As for what he deserved…who knows?."

Charlie climbed out of the car, steadying himself against the door for a nauseous moment: time for a few more of those hospital painkillers. He leaned down to look through the window at Amita, still behind the steering wheel. "Schlick was killed in the central stairway of the main university building while he was rushing to get to a lecture." Charlie heard the bitterness creeping into his voice, told himself to shut up and then ignored his own advice. "Apparently his students—one student in particular—knew he was habitually late to class, not unlike some professors at CalSci. Someday, when you're a professor and you go to Vienna for a conference, you'll have to go see the place; they have brass marker on the floor where it happened."

He was trying to unlock the front door when he heard her car door close. He didn't answer when she called his name. Surprisingly tricky to work a key with your non-dominant hand.

"Charlie," she said again, not moving from her place in the driveway, "what bothers you most about this?"

Something snapped inside him then, because that was the question he always asked. When his students were confused by too many variables or when they didn't know how to start a proof, Charlie would always tell them to pick just one problem, one facet of one problem, the one that bothered them most. God, he was tired. He wanted to tell Amita to get lost; he wanted to go upstairs to his room, climb into bed, and think about cubes until he fell asleep. He looked down the steps to where Amita was waiting. She looked uneasy and a little belligerent, aware that he might snap at her again, but determined to get the answers she'd come for. With an attitude like that she would make a hell of an impression on Vienna.

Finally, Charlie made up his mind. "Amita," he said civilly, dredging up everything his mother had ever taught him, "would you like to come inside? I don't know what we have in the way of food, but I can certainly offer you some lemonade."