Ludmila frowned. “I did, and now I wonder if I should have. That’s why I wanted to let you know: in case I was stupid.”

Anielewicz grew alert. “Why? Do you think he was a Polish nationalist? Or did he like a Nazi talk?” He smiled as he put on the German accent, but the expression didn’t reach his eyes. He’d done the Greater German Reich a few favors during the fighting, but he’d done the Nazis any number of unfavors during it and since, not least refusing to let himself and Lodz go up in fire when the SS smuggled what was now the Jews’ explosive-metal bomb into the city.

“No.” Ludmila shook her head. “And no again. As a matter of fact, he spoke Polish the same way I do. Not as well, I don’t think.”

“A Russian?” Mordechai asked, and she nodded. Now he frowned. “What would a Russian want with me? I haven’t had anything to do with Russians… for a while.” Ludmila was his dear friend, but that didn’t mean she needed to know everything he did as one of the leaders of Poland’s Jews. She nodded again, understanding as much. He shrugged. “Isn’t that interesting? All right, I’ll keep an eye open for Russians. Can’t trust those Reds, after all. You never know what they might do.”

“No, you never know.” Ludmila, former Red Air Force senior lieutenant, smiled at him. “Reds are liable to do all sorts of foolish things. They might even decide they like living in Poland.”

“Oh, I doubt that,” Mordechai said. They both laughed. He went on, “I wonder what the fellow wants with me. I know some Russians-some Russians in Russia, I mean-but if they need to get hold of me, they know how.”

Ludmila looked troubled. “Maybe I shouldn’t have told him anything. But I didn’t think it could do any harm.”

“It probably won’t,” Anielewicz said. “Don’t worry about it. I don’t intend to.” He brought his feet back up onto the bicycle pedals and rode off. When he looked back over his shoulder-not the safest thing to do in the narrow, crowded, winding streets of Lodz-he saw Ludmila walking along with the same limping determination she’d shown ever since coming to the city. She never said anything more about the nerve gas that still tormented her than nichevo — it can’t be helped. Heinrich Jager had been the same way till the aftereffects of the gas helped put him in an early grave.

As Mordechai pedaled back toward his flat, he kept on pondering what Ludmila had told him. He couldn’t make heads or tails of it. Russians who dealt with him in official ways necessarily knew how to reach him. Those who dealt with him in unofficial ways, as David Nussboym had, could also get hold of him whenever they needed to. But he didn’t think he’d be seeing Nussboym, officially or unofficially, for a long time, if ever. By the word that filtered out of the Soviet Union, the NKVD was still being purged. Odds of Nussboym’s survival didn’t strike Mordechai as good.

“And I won’t miss him a bit,” he muttered as he stopped in front of his block of flats. But what did that leave? After a little while, he realized it might leave a Russian who had nothing to do with the government of the Soviet Union. That government was so allembracing inside the USSR, it was no wonder the thought had taken so long to occur to him. The wonder was, he’d come up with it at all.

When he got up to the flat, he asked his wife if anybody speaking Polish with a Russian accent had come around looking for him. “Not that I know of,” Bertha answered. She turned to their children, who were doing homework at the kitchen table. “Has anyone with a funny accent been asking for your father?”

Heinrich Anielewicz shook his head. So did his older brother David and their older sister Miriam. “Isn’t that peculiar?” Mordechai said. “I wonder who the fellow is and what he wants.” He shrugged. “Maybe I’ll find out, maybe I won’t.” He started to shrug again, then paused and sniffed instead. “What smells good?”

“Lamb tongues,” Bertha answered. “They’re usually more trouble than they’re worth, because it’s so hard to peel off the membrane-it comes away in little pieces, not in big chunks like a cow’s-but the butcher had such a good price on them that I bought them anyhow.”

David said, “I hear the Lizards have such sharp teeth, they can eat tongues and things like that without peeling them.” Heinrich and Miriam both looked disgusted, which had to be part of what he’d had in mind when he spoke up.

“If you remembered your Hebrew half as well as the things you hear on the street, you wouldn’t have to worry so much about your bar mitzvah next month,” Mordechai said.

“I’m not worried, Father,” David answered. That was probably true; he had an easygoing disposition much like his mother’s. Mordechai was worried, though. So was Bertha, even if she did her best not to let it show. They would go right on worrying till the momentous day had passed, too. Having a son who excelled at his bar mitzvah was a matter of no small pride among the Jews of Lodz.

Over the supper table, in between bites of flavorsome tongue (the lamb tongues might have been a lot of trouble to make, but turned out to be worth it), Heinrich asked, “Father, what’s an irrational number?”

“A number that drives you crazy,” David put in before his father could answer. “The way you do arithmetic, that’s most of them.”

Mordechai gave him a severe look and Heinrich a curious one. Mordechai knew something about irrational numbers; he’d studied engineering before the Germans invaded Poland and turned his life upside down. “You’re just barely nine years old,” he said to his younger son. “Where did you hear about irrational numbers?”

“A couple of my teachers were talking about them,” Heinrich answered. “I thought they sounded funny. Are they crazy numbers, or numbers that make you crazy, the way David said?”

“Well, they call them that because they used to drive people crazy,” Mordechai said. “They go on forever without repeating themselves. Three is just three, right? And a quarter is just.25. And a third is.33333… as far as you want to take it. But pi-you know about pi, don’t you?”

“Sure,” David answered. “They have us use three and a seventh when we figure with it.”

“All right.” Anielewicz nodded. “But that’s just close-you know what an approximation is, too, right?” He waited for his son to nod, then went on, “What pi really is, at least the start of it, is 3.1415926535897932… and it’ll go on forever like that, not repeating itself at all. The square root of two is the same kind of number. It’s the first one that was ever discovered. The ancient Greeks who found it kept it a secret for a while, because they didn’t think there should be numbers like that.”

“How did you remember all those decimal places for pi?” Miriam asked.

“I don’t know. I just did. I used to know a lot more, even though they’re pretty much useless after the first ten or so,” Anielewicz answered.

“I could never remember so many numbers all in a row,” his daughter said.

He shrugged. “When you play the violin, you remember which note goes after which even when you haven’t got the music in front of you. I couldn’t do that to save my life.”

“I know.” Miriam sniffed. “You can’t carry a tune in a pail.”

He would have been more offended if she’d been lying. “I can remember numbers, though,” he said. Miriam sniffed again. He could hardly blame her; set against musical talent, that didn’t seem like much. “Every once in a while, it comes in handy.” Having said that, he’d said everything he could for it.

After supper, the children went back to their books. Then Miriam practiced the violin for a while. David and Heinrich played chess; David had taught his brother how the pieces moved a few weeks before, and took no small pleasure in beating him like a drum. Tonight, though, he let out an anguished howl as Heinrich forked his king and a rook with a knight.