"Looks like it . . ." Hunt's voice sounded far away.

"Mmm . . . rows and columns . . . thick lines and thin lines .,. Could be anything—mileage chart, wire gauges, some sort of timetable. Who knows?"

Hunt made no reply but continued to blow occasional clouds of smoke at the glass, cocking his head first to one side and then to the other.

"None of the numbers there are very large," he commented after a while. "Never more than two positions in any place. That gives us what in a duodecimal system? One hundred and forty-three at the most." Then as an afterthought, "I wonder what the biggest is."

"I've got a table of Lunarian-decimal equivalents somewhere. Any good?"

"No, don't bother for now. It's too near lunch. Maybe we could have a look at it over a beer tonight at the Ocean."

"I can pick out their one and two," Gray said. "And three and . . . Hey! What do you know—look at the right-hand columns of those big boxes. Those numbers are in ascending order!"

"You're right. And look—the same pattern repeats over and over in every one. It's some kind of cyclic array." Hunt thought for a moment, his face creased in a frown of concentration. "Something else, too—see those alphabetic groups down the sides? The same groups reappear at intervals all across the page . . ." He broke off again and rubbed his chin.

Gray waited perhaps ten seconds. "Any ideas?"

"Dunno . . . Sets of numbers starting at one and increasing by one every time. Cyclic . . . an alphabetic label tagged on to each repeating group. The whole pattern repeating again inside bigger groups, and bigger groups repeat again. Suggests some sort of order. Sequence . . ."

His mumblings were interrupted as the door opened behind them. Lyn Garland walked in.

"Hi, you guys. What's showing today?" She moved over to stand between them and peered into the tank. "Say, tables! How about that? Where'd they come from, the books?"

"Hello, lovely," Gray said with a grin. "Yep." He nodded in the direction of the scanner.

"Hi," Hunt answered, at last tearing his eyes away from the image. "What can we do for you?"

She didn't reply at once, but continued staring into the tank.

"What are they? Any ideas?"

"Don't know yet. We were just talking about it when you came in."

She marched across the lab and bent over to peer into the top of the scanner. The smooth, tanned curve of her leg and the proud thrust of her behind under her thin skirt drew an exchange of approving glances from the two English scientists. She came back and studied the image once more.

"Looks like a calendar, if you ask me," she told them. Her voice left no room for dissent.

Gray laughed. "Calendar, eh? You sound pretty sure of it. What's this—a demonstration of infallible feminine intuition or something?" He was goading playfully.