receive a parcel o' rogues from the Aliens Office under circumstances of the utmost secrecy. Now, sir—this is intolerable! I will not be kept in ignorance. You will tell me what is afoot this instant, sir.'
Kydd swallowed. 'Sir, I—I cannot. The Aliens Office?'
'Are you asking me to accept that a—a junior commander is to be made privy to matters considered too sensitive for a senior admiral? Have you been politicking, sir? I won't stand for it in a serving captain of mine, Mr. Kydd, no, not for one minute.'
'N-no, sir.'
'And I intend to be present when those jackanapes arrive!'
'Of course, sir.'
'Most irregular!'
'Yes, sir, it is.'
'You'll wait here until sent for,' Keith rumbled irritably. 'You may not leave on any account.'
'Aye aye, sir.'
Sitting alone in the little side office, Kydd waited apprehensively.
Late in the afternoon he heard a commotion in the outer office: raised voices, scraped chairs and hurrying footsteps. Moments later, two travel-dusty men strode in, closely followed by a red-faced Keith.
'This is insupportable! I will not have it! This officer is under my command and—'
'Sir. We take our instructions from the foreign secretary directly, this being as grave a matter as any that has faced this kingdom.' The taller individual sniffed. 'You have a telegraph, sir. If you have any doubts . . .'
He waited pointedly until the admiral had left them, then addressed Kydd: 'From this point on everything that is said shall be at the highest possible level of secrecy. Do you understand me?'
'I know my duty, sir.'
'Very well.' He opened his dispatch case and extracted a small packet, the seal broken. 'What do you understand by this?'
Kydd took it and went cold. 'Why, this is from my ship's clerk and good friend. Where is he—'
'That will be of no concern to you. Can you say any more?'
'Er, unless I might read the contents?'
'No, sir, you may not,' he said, taking it back. 'Please answer me directly. Was there any arrangement between you touching on the transmission of privileged information?'
'None. He's in a—a difficulty of sorts, is he?' Kydd said uneasily.
The two exchanged looks. 'He is performing a mission of the utmost importance that is proving unfortunate in its complexity,' the taller man said carefully. 'You may know that what you hold is a form of communication that is strongly ciphered. We do not possess the key, however, and believe that his referring to yourself implies it may be found by reference only to you.'
Kydd was dumbfounded. 'We've never discussed anything in the character of spying—nothing! Renzi wholly detests it, you may believe.'
'Then this leaves us in a difficult position indeed,' the man continued heavily. 'If you know of nothing he has said, no paper to keep guarded, no locked cabinet . . . ?'
'I do not.'
'Nothing whatsoever that may lead us to a key?'
'Tell me, this key, how would I know it?'
The other man broke in, his dry voice calm. 'Mr. Kydd, the practice of privy communications is a black art but has a number of inviolable axioms, one of which is that the receiver must be in possession of the same key that was used to encode the message, without which he is helpless.
'It is the usual practice to establish a key beforehand, else we shall be obliged to transmit the key by other means, a most unsatisfactory and hazardous proceeding. In this particular case we have no prior arrangement and the key not being onpassed therefore must exist here, and be alluded to. The only clue we have is what you see before you. Your name has been invoked and that is all. A masterly stroke, which is its own guarantee of security but, regrettably, leaves us in a quandary.
'As to its appearance, well, a key can be of many forms—an arithmetical formula, a grid of nonsense, a passage in a book and in fact anything—but without it . . .'
Kydd realised that the men would not have acted as they had unless the matter was vitally important, and Renzi would not have given his name unless he himself was the key.
'Show me the message,' he demanded.
Reluctantly it was handed over. Kydd examined it minutely: it was in his friend's hand but consisted of lines upon lines of meaningless letters in groups of five and covered several pages. A few mistakes were blotted out and there were one or two crossed-out sequences in the margin, but that was all. It was not signed, and the beginning was only a bare date on one side, with what looked like a doodle on the other. No doubt it had occupied lonely hours of danger for Renzi.
He looked at the little picture. It was a stylised open book and a fat exclamation mark next to it as though in exasperation at the tedium of the task. Was this a sign—or a pointer of some kind? A clue?
Then he had it! 'Why, I think I know what it is. A passage from a book, you said. Will a poem do at all?'
'Yes, damn it!'
