“You’re dealing with material encyphered by a great many different routes and often you’re handling several programmes simultaneously. The more cyphers and the more programmes, the greater the risk that something from one programme will coincide with something from another and make nonsense.”
Unexpectedly Hogben and Miss Prinkett beamed at him. The latter said, “I’ve been trying to make them understand that since yesterday afternoon!”
Sir Andrew said hastily, “Well, Dr Molesey, can you hold out any hope?”
“Hope?” Molesey repeated, frowning. “Oh, certainly. But no promises.” He glanced at his watch, comparing what it told him with the wall-clock. “Do you want us to start work right away? I see it’s nearly five-thirty, and—”
He broke off. Sir Andrew was glaring ferociously.
“Are you mad?” he thundered. “Thirty-five million pounds of public money we paid your company for these computers, and they’ve broken down! You are damn well going to stay here until they’re working properly again!”
The trouble-shooting team exclaimed in unison. He refused to listen.
“I’ll arrange for messages to be sent to your families apologising for your absence. Next door you’ll find bunks, and a bathroom, and I’m told the canteen provides edible food. But you do not and I repeat not leave hear until you’ve repaired this abominably expensive pile of tinware! Now you must excuse me. I have a date for dinner with my Minister.”
He marched out, with Dr Finbow in his wake. The door swung to.
Hogben sank his fingers in his lank dark hair.
“Typical,” he muttered. “Bloody typical. They wouldn’t stand a chance in a million of even finishing a course in computer studies, and they expect everybody else to work miracles on their behalf. Dilys and I have been on the job, like I told you, since about an hour after the trouble came to light, and we kept going all last night on pills and no sleep. I feel awful. . . Suppose one of you brings some chairs from next door, hm? Then I can tell you what we already know, and after that we absolutely must flake out.”
Desmond reacted with alacrity. Beyond the door he found a short, bare corridor from which three doors led off. One was marked WASHROOM; the next was the entrance to the lift they had come down in; the third proved to lead into a room where four bunks, a stack of chairs and some shelving provided the only furniture. Both in the corridor and in the room more TV cameras were on watch.
He returned, carrying six of the light plastic chairs, with a curious tingling sensation on the nape of his neck.
They sat down in a close circle, elbows on knees, to hear what Hogben had to tell them.
“If it isn’t in the hardware,” he expounded, “it’s more likely to be in the cypher zone than anywhere else, right? The first conclusion Dilys and I jumped to was the obvious one: the alphabet-selection system slipped a gear and the machines are trying to decrypt stuff in today’s cypher using yesterday’s or maybe tomorrow’s keys.”
Molesey said acutely, “You don’t actually mean that, do you? Surely the alphabets are changed a lot more often. Say about every ninety minutes.”
“It’s randomised,” Dilys Prinkett said. “But—yes, it averages out to about fifteen changes a day, more or less.” Removing her glasses, she rubbed her eyes; the left was very bloodshot.
“Just to complicate things,” Hogben said, “the choice of alphabet-group depends on the addressee of the message. Each embassy has a different selection!”
Claude Vizard burst out, “You mean you have to try and match every last message to all the alphabet-groups that were in use, and what’s more check backward and forward in time too?”
“That’s what we would dearly like to do,” Hogben said. “Only we can’t. We can’t get at the store where they keep the alphabets. Before we can start trying to unscramble the mess we have to have some sort of guide. Which means that tape reels containing the locally assigned cyphers are going to have to be brought back from all our embassies by hand of Queen’s Messenger.”
“That could take weeks,” Molesey said.
“Don’t we know it!”
“So . . .” Molesey hesitated. “So what exactly do they expect you to do, let alone us?”
“It was our bad luck,” Hogben said around a yawn, “that we half-broke the jam immediately. When they sent for us—we’re Sir Andrew’s special pets, apparently, though I think he must hate us more than he likes us because we get all the lousiest assignments . . . Where was I? Oh, yes. They were getting blank screens and no onward transmission. We came charging in and blithely said, ‘No problem! It’s just the cypher-synch gone out of kilter—look!’ Bingo, the screens lit up for us. Only they proceeded to show this ridiculous garble.”
Absently he tapped a code into the remote again; the screens replied with another selection of incomprehensible letters: HJVGR WROPA MCRKE . . .
“Which,” Dilys Prinkett sighed, “at once convinced them we could work the rest of the trick. Even when we’d discovered that we couldn’t, they took until now to believe we needed help. Well, at least you finally showed up. Can we kip down, please? I’m so tired . . .”
Barring a short break to eat a hasty meal, which failed to live up to Sir Andrew’s assurances about edibility, the team hammered away at the job until past one in the morning. They ruled out one fault after another, confirming as they did so two of Acey-Acey’s most cherished advertising claims: that their gear was exceptionally reliable, and that fault-tracing on the X Ten Thousand was exceptionally easy.
But even when, using a phone in one corner of the room, they called for and were brought a substitute portable read-in—just in case the flaw lay there rather than in the main part of the machinery—they found nothing wrong at
