‘A killer with a conscience?’

‘That’s right. For your own good, Captain, we’ve never had this conversation. This goes so high it’d make your head spin. You risk annoying some forceful people. Can’t imagine what the going rate is for making a Commander of the CID disappear but there’s bound to be one.’

‘But what possible danger could she be to the state?’ Joe persisted. ‘Playing Girl Guides with a bunch of silly debutantes and the lout Donovan?’

He was pleased to have provoked the response he wanted.

‘Not silly girls at all! Clever, able, well-trained girls.’ Armitage hesitated, weighing the knowledge that he was exceeding his brief against his understanding of his superior officer which was pushing him beyond his limits. He came to a decision. ‘Girls who, though they were unaware of it,’ he went on, ‘had, in their charming little heads, the power to lose the next war for us.’

‘Lose a war, Bill? But they were training to help win wars.’

‘Tell you a story.’ He leaned back and Joe had a clear impression that he was about to call up a brandy and soda. ‘Know who I mean when I mention Admiral Sir John Fisher?’

‘Of course. Father of the modern navy . . . innovator . . . brilliant man. Destroyers, submarines, torpedoes, guns – he was responsible for the state of readiness of the fleet when war broke out. It was Jack Fisher who said: “On the British fleet rests the Empire.”’

‘And he wasn’t wrong. It was his protégé, Admiral Jellicoe, who actually led the fleet into battle. Now, the Germans were caught on the back foot on several occasions early in the war because Jellicoe always seemed to know where and when they were massing for attack. The reason he was able to give them a bloody nose was the SIGINT warnings to Room 40. Signals Intelligence. Wireless telegraphy, radio, whatever you like to call it. Their shipping movements were being monitored, the information collated and interpreted and handed to Jellicoe on a plate. He and Admiral Beatty were on their way while the German fleet was still in harbour. At the battle of Jutland, he had victory in his pocket and the German fleet trapped at night in open waters at the entrance to the Skaggarak. He was ready to blow them out of the water come dawn but – he faltered. He was given signals information and he ignored it. Let them get away. No one’s quite sure why.’

Joe wondered why Armitage was imparting this information so freely and who was his source. He had remarked an unusual political slant which didn’t quite chime with what he had understood to be Armitage’s philosophy.

‘Jellicoe decided to accept instead the inaccurate information from his scouting cruisers,’ Armitage revealed, watching for Joe’s reaction. ‘Reverted in the middle of battle to the tried and tested old methods. If he’d acted in accordance with radio intelligence supplied, which was very clear as to the position of the High Seas Fleet, Jutland might have turned out really to be the victory Churchill told us afterwards it had been and not the uncomfortable and bloody draw it actually was.’

‘Why was the intelligence not acted on? Do you – or your masters – have a theory, Bill?’

‘You fancy yourself as a psychologist – you tell me! There is a phrase they’ve invented to cover it: the Incredulity Factor. A sudden refusal to put your trust in modern technology.’

‘I know it well,’ said Joe. ‘It affects me every time I change gear.’

He thought he would get the most out of Armitage by keeping their exchanges as light as possible and maintaining, as far as he could, their old relationship. ‘But I do begin to see how a well-placed squad of Wrens could wreak havoc at sea,’ he added carefully.

‘Yes, there’s no doubt that Jellicoe’s hesitation was due to incredulity but – think! Suppose a wireless operator had been in a position to send him a further communication confirming his own doubts. “Ignore previous message . . . we got it wrong . . . HSF now reported sailing west . . .” Bound to have influenced his decision!’

‘Certainly. We all like to have support for our own misjudgements.’

Armitage looked at him steadily for a moment then continued: ‘The navy was pivotal. If the Germans had destroyed us at sea in 1916 and blockaded the country – no supplies coming in and no troops going out – we’d have been on our knees in six months.’

Joe knew Armitage was not exaggerating when he said, ‘One duff message, Captain, that’s all it would take.’

Joe’s reply came haltingly, unwillingly. ‘And if the sender has knowledge of the language, coding, wireless technology . . . and – perhaps most vital – an understanding of overall strategy . . . Oh, my God! But would a woman ever be given such an influential role?’

The full enormity of the scenario had hit Joe and he shuddered.

‘It didn’t take the navy long to discover the girl recruits were smarter than the men when it came to SIGINT and they’re nothing if not innovators at the Admiralty – if it works, use it. If war were to break out again, I’d expect Queen Bea’s girls or the like to be operating in the signals section. Wireless, signals, codes. The next lot will be won or lost in the airwaves not in the trenches. One bad communication from a trusted source at a critical moment, that’s all you’ll need!’

At last Joe was in possession of the awful truth.

‘Are you saying the Dame was preparing to betray her country to the Bolsheviks?’

Armitage’s laugh was derisory and triumphant. ‘God no! I never thought I’d hear myself say it but – you’re wrong on two counts there, Captain!

‘For a start, her country, the one she really paid allegiance to, was not England. Given the chance, she was intending to foul up things for the British fleet and bring about a victory for the country she truly cared about – Germany.’

Joe felt suddenly awash with horror. Armitage must have been watching his every movement intently. He produced his brandy flask. ‘Gulpers, I’d say, sir. Go on!’

Joe was thankful for the warmth searing its way down his throat. Too late he remembered who had offered the drink.

‘It’s all right,’ said Armitage, amused. ‘Only the best scotch in there. I’ll have one myself.’

‘What a headache she must have given the various departments once they found out! But how did they get to hear?’

‘One of the girls who killed herself – no idea who . . . no need for me to know that – is understood to have written a letter to her highly placed father confessing all and warning him. Action was swiftly taken.’

‘Ah! The sting!’ Joe mused. ‘The venomous shaft she placed killed the victim but brought her own death with it. I like a neat, classical ending! But I see the problem: difficult to charge her with anything because, technically, she’d done nothing wrong. Her crime was in the future. Conspiracy, perhaps?’

‘You’re forgetting the friends in high places.’

‘Couldn’t one of them have been primed to take her out on to some terrace and hand her a brandy and a revolver, in the good old British tradition?’

‘There’d still have been public interest aroused. And these days we have to consider the reactions of the bloody press at every turn. They don’t just turn up and meekly take dictation from the Home Office any more. She was a colourful woman and very much in the public eye. There’d have been talk in any circumstances – but the tragic, though understandable, death at the hands of a burglar is a nine-day wonder. Cat burglars have become a national obsession – everyone was expecting something like this to happen. Just a question of time. She was unlucky. No one minds the press running with that story – let them enjoy it. But think, sir . . . if the truth came out about the Queen Bea . . . Remember the scandal of the trial of Sir Roger Casement after the war. We’re still in the outfall of that seven years on.’

‘And he was an Irishman! How much worse if a woman regarded by some as an English heroine were similarly exposed!’