“Ah.” Diebner turned his head, peered this way and that; unlike Jager and Heisenberg, he was careful about who heard him speak. His big thick spectacles and their dark rims gave him the air of a curious owl. “Sometimes, Colonel Jager,” he said when he was sure the coast was clear, “from the top of the ivory tower it is hard to see the men struggling down in the mud.”

“This may be so.” Jager studied Diebner. “And yet-forgive me, Herr Doktor Professor-it seems to me, a colonel of panzers admittedly ignorant of all matter pertaining to nuclear physics, that you, too, dwell in this ivory tower.”

“Oh, I do, without a doubt.” Diebner laughed; his plump cheeks shook. “But I do not dwell on the topmost floor. Before the war, before uranium and its behavior became so important to us all, Professor Heisenberg concerned himself almost exclusively with the mathematical analysis of matter and its behavior. You have perhaps heard of the Uncertainty Principle which bears his name?”

“I’m sorry, but no,” Jager said.

“Ah, well.” Diebner shrugged. “Put me in charge of a panzer and I would be quickly killed. We all have our areas of expertise. My gift is in physics, too, but in experimenting to see what the properties of matter actually are. Then the theoreticians, of whom Professor Heisenberg is among the best, use these data to develop their abstruse conclusions over what it all means?”

“Thank you. You have clarified that for me.” Jager meant it-now he understood why Heisenberg had sneeringly called Diebner a tinkerer. The difference was something like the one between himself and a colonel of the General Staff. Jager knew he didn’t have the broad strategic vision he’d need to succeed as a man with the Lampassen-the broad red stripes that marked a General Staff officer-on his trousers. On the other hand, a General Staff officer wasn’t likely to have acquired the nuts-and-bolts knowledge (often in the literal sense of the words) to run a panzer regiment.

Diebner said, “Do try to bear with us, Colonel. The difficulties we face are formidable, not least because we are under such desperate pressure of time and strategy.”

“I follow,” Jager said. “I wish I were back with my unit, so I could use what I have learned to help hold the Lizards out of the Reich and let you complete your work. I am badly out of place here.”

“If you advance our building of the uranium bomb, you will have done more for the Reich than you could possibly accomplish in the field. Believe me when I say this.” Now Diebner looked earnest, like a farmer solemnly explaining how excellent his beets were.

“If.” Jager remained unconvinced that he could do anything useful here at Hechingen: he was about as valuable as oars on a bicycle. He came up with a plan, though, one that made him smile. Diebner smiled back; he seemed a very decent fellow. Jager felt a little guilty at going against him, but only a little.

When he got back to his quarters, he drafted a request to be returned to active duty. On the space in the form that asked his reason for seeking the transfer, he wrote, I am of no use to the physicists here. If confirmation is required please inquire of Professor Heisenberg.

He sent the request off with a messenger and awaited results. They were not long in coming-the application got approved faster than he had thought possible. Diebner and a couple of the other physicists expressed regret that he was leaving. Professor Heisenberg said not a word. He’d no doubt had his say to the office who’d called or telegraphed about Jager.

Maybe he thought he’d had his revenge. As far as Jager was concerned, the distinguished professor had done him a favor.

Yea, though I walk through the valley of the shadow of death, I shall fear no evil, for Thou art with me. Lodz constantly put Moishe Russie in mind of the Twenty-third Psalm, and of that valley. Lodz, though, had only walked into the valley, not through it. The shadow of death still lay over the town.

In Warsaw, thousands in the ghetto had died of starvation and disease before the Lizards came. Starvation and disease had walked the streets of Lodz, too. But the Nazis hadn’t let them work alone here. They’d started shipping Jews off to their murder factories. Maybe the memory of those death transports was what made Lodz still seem caught in the grip of a nightmare.

Russie walked southeast down Zgierska Street toward the Balut Market square to buy some potatoes for his family. Up the street toward him came a Jewish policeman of the Order Service. His red-and-white armband bore a six-pointed black star with a white circle in the center, marking him as an underofficer. He had a truncheon on his belt and a rifle across his back. He looked like a tough customer.

But when Russie tugged at the brim of his hat in salute, the Order Service man returned the gesture and kept on walking. Emboldened, Russie turned and called after him: “How are the potatoes today?”

The policeman stopped. “They’re not wonderful, but I’ve seen worse,” he answered. Pausing to spit in the gutter, he added, “We all saw worse last year.”

“Isn’t that the sad and sorry truth?” Russie said. He headed on down to the market while the Order Service man resumed his beat.

More policemen roamed the Balut Market square, to keep down thievery, maintain order-and cadge what they could. Like the underofficer, they still wore the emblems of rank they’d got from the Nazis.

That helped make Lodz feel haunted to Russie. In Warsaw the Judenrat-the Jewish council that had administered the ghetto under German authority-collapsed even before the Lizards drove out the Nazis. Its police force had fallen with it. Jewish fighters, not the hated and discredited police, kept order there now. The same held true in most Polish towns.

Not in Lodz. Here, the walls of the buildings that fronted the market square were plastered with posters of balding, white-haired Mordechai Chaim Rumkowski. Rumkowski had been Eldest-puppet ruler-of Lodz’s Jews under the Nazis. Somehow, he was still Eldest of the Jews under the Lizards.

Russie wondered how he’d managed that. He must have jumped from the departing train to the arriving one at just the right instant. In Warsaw, there were stories that he’d collaborated with the Nazis. Russie had asked no questions of that sort since he got into Lodz. He didn’t want to draw Rumkowski’s attention toward him and his family. For all he knew, the Eldest would turn him over to Zolraag, the local Lizard governor.

He got into line for potatoes. The lines moved fast; the Order Service men saw to that. They were fierce and fussy at the same time, a manner they must have learned from the Germans. Some of them still wore German-style jackboots, too. As with the ghetto stars on their armbands, the boots raised Russie’s hackles.

When he reached the front of the line, such worries fell away. Food was more important. He held out a burlap bag and said, “Ten kilos of potatoes, please.”

The man behind the table took the bag, filled it from a bin, plopped it onto a scale. He’d had endless practice; it weighed ten kilos on the dot. He didn’t hand it back to Russie. Instead, he asked, “How are you going to pay? Lizard coupons, marks, zlotys, Rumkies?”

“Rumkies.” Russie pulled a wad of them out of his pocket. The fighter who’d driven him into Lodz had given him what seemed like enough to stuff a mattress. He’d imagined himself rich until he discovered that the Lodz ghetto currency was almost worthless.

The potato seller made a sour face. “If it’s Rumkies, you owe me 450.” The potatoes would have cost only a third as many Polish zlotys, the next weakest currency.

Russie started peeling off dark blue twenty-mark notes and blue-green tens, each printed with a Star of David in the upper left-hand corner and a cross-hatching of background lines that spiderwebbed the bills with more Magen Davids. Each note bore Rumkowski’s signature, which gave the money its sardonic nickname.