Chapter Ten

“Fate,” said “Blinker” Hall, “has played many dirty tricks on me in my life, but none dirtier than this one. I was appointed, last week, to head the Naval Intelligence Division – as I’m sure you heard.” Kell nodded. “Two days ago I took up my duties, to be presented, immediately, with one of the most important matters that has faced the division since the outbreak of war.”

Kell made a noise that expressed surprise and sympathy. He said, “We all heard the explosion, but as there was an immediate blackout on all news – quite rightly, I’m sure – we’ve heard no details.”

“Yesterday afternoon H.M.S. Bulwark, one of our fifteen thousand-ton battleships, at anchor off Sheerness, was almost completely destroyed by an internal explosion, which also killed five hundred men and officers.”

“And no one has any idea what caused it?”

“Plenty of ideas. No proof. The story we’re putting about – which is the truth, as far as we know it – is that there was an explosion in the ship’s magazine.”

“And as to what caused it …?”

“A dozen explanations, from an electrical fault in the hoisting gear to a stoker dropping a lighted cigarette.”

“And you don’t believe any of them. You think it was deliberate sabotage.”

“It’s a horrible thought. But, yes, that’s what I do think. And I’m devoid of ideas as to how to prove it. That’s why I’ve come to you, to pick your brains.”

Kell said, “Well, I can give you a few preliminary ideas, most of which you’ll have thought of already. If the explosion was organised by a German agent, he must have suborned at least one member of the crew.”

“I’m afraid you’re right. Have you any idea, at all, where such an agent might be located?”

Kell said, “We’re progressing – if that isn’t too grand a word – in two fields and suffering from an acute shortage of manpower in both of them. A lot of my best men have been drafted into the Intelligence Corps in France. And I nearly lost another good man when Hubert Daines was roughly handled by some of the dockland Irish. He’ll be out of the hospital soon, but will need a bit of leave before he continues as head of our investigations in the East End. It’s a promising field. More promising still if I could equip him with a proper team. I’m better off than I was, but still desperately shorthanded for all the work I’m supposed to do.” Kell snorted. “I’m sure my opposite number in Germany has two or three hundred trained men at his beck and call. Daines has been struggling along with two men and a boy. Luke Pagan—I think you met him …”

“Found him on a rock,” murmured Hall.

“And his friend Joe Narrabone, formerly with Pagan in H Division of the Metropolitan Police.”

“Lost a leg in the Leman Street explosion, didn’t he? Ex poacher and bad boy of the village.” Hall had clearly done his homework. “Who’s the other one?”

Kell explained about Lefroy. When he had finished, the two men sat in silence for some time, each busy with his own thoughts.

Hall said, “You mentioned two fields.”

“The other one is the Mount Pleasant sorting office. We’re still patiently examining the in-and-out mail of possible suspects, but I’m not convinced that two men can handle the job properly. They photograph and file any letters that look interesting, but, as you can imagine, since war was declared extreme caution has set in. What I’d like to do is not just photograph the letters, but test them for possible writing in invisible ink.”

“They do that, do they? I suppose there’s some method of developing it.”

“Several different ways. They might be using lemon juice, or saliva, or even diluted milk. The lemon juice can be brought out by applying a hot flat iron. The saliva by having ordinary ink brushed lightly over it. And—what did I say was the third?”

“Diluted milk,” said Hall. He had been making notes. He found details of this sort fascinating.

“Oh, yes. That’s one of the most difficult methods. The writing is totally invisible in any light, and to bring it out you have to dust it over with graphite powder. You can imagine that with our present staff we have little time for refinements of that sort.”

Hall said, “Suppose I was able to find you three or four intelligent naval officers – they’d be men who were too old for active service, or may be crippled. Would you be able to use them?”

“My dear fellow,” said Kell. “Manna in the wilderness. I’ll use any number you can spare.” As Hall rose to go, he added, “I’ve been invited to visit the Explosives Testing Centre on Duck Island. That’s on—let me check—yes. Thursday afternoon. Would you care to come along?”

“Delighted,” said Hall.

“One thing they’re investigating is the possibility of dropping bombs onto selected targets from the air. I suggest that you find out – Antiaircraft Command will be able to tell you – whether there were any Zeppelins over Sheerness at the time of the Bulwark explosion, or even a day or two before it.”

Hall said that he would do this. He looked a little happier than he had on arrival.

When Luke went, on that same afternoon, to report the results of his visit to the arsenal, he found Kell in a relaxed and equable mood. More than relaxed. He was positively glowing with pleasure. The offer that Hall had made him, if it could be developed into full-scale liaison between the Naval Intelligence Division and MO5, would more than double the efficiency of both.

He listened to what Luke had to tell him and said, “It sounds pretty watertight to me. Could you spot any loopholes?” For a precise speaker like Kell, such a mixing of metaphors was a further indication of geniality.

“Not really, sir. Just one reservation: the sentries who were manning the footway behind the wall were mostly old soldiers. Eight-hour shifts, with a dog watch every twenty-four, is not an easy stint, even for a young man. When I mentioned it, the colonel produced an argument that I found difficult to shout down. He said, ‘Men in the trenches serve longer hours than that and aren’t half as comfortable.’ Which is true, of course. Here they can get hot baths when they want them, and, I believe, a supplementary ration on account of the work they’re doing.”

“I suppose that’s right,” said Kell. “As long as they don’t fall asleep on the job. I’ve set up a meeting on Thursday afternoon with Major Cooper-Key, the chief inspector of explosives. You’d better come along. I’m hoping he’ll be able to give Hall some theory to account for what happened to the Bulwark.”

The Explosives Testing Centre, on and under Duck Island, was a humpbacked construction of concrete blocks with a number of sandbagged enclosures around it. The ducks, after whom the island had been named, had long since departed to a less disturbed home.

The presiding deity, Major Cooper-Key, was not unlike a member of the grallatores, or wading birds, being long and thin and equipped with a prominent beak, well adapted for poking under stones. Sitting beside him was Dr. Duprès, the chemical analyst; a perfect contrast – tubby, balding, and with thick-lensed glasses wedged onto a snub nose.

“I’ve got two theories for you,” said the major. “One has been worked out by my department. The other is the brainchild of my friend.” Dr. Duprès ducked his head briefly. “The attack, as we see it, might have come from above or from below.”

(“Über und unter,” the German naval officers in the Royal Duke had chanted.)

“My own theory is of a mechanical attack from above. It presupposes a visit from one or more Zeppelins.”

Hall said, “I’ve checked with AA Command. They tell me that two Zeppelins were over Sheerness the day before the explosion on the Bulwark.”

“When you say the day before, do I assume that you mean the evening before?”

Hall said, “That’s correct. The first sighting was at 2035 hours. It would have been dusk, but not yet dark. Why? Does something turn on it?”

“Yes, Captain. I think it does.”

The major picked up the curious object that had been on the table in front of him. It was a fat, metal tube, about eighteen inches long and four inches round, with a small propeller at one end. Grasping it firmly, the major unscrewed it and held it up for their inspection.

As far as they could make out, the interior was in two sections, divided by a membrane.

“This little joker was thrown into an ammunition ship in New York and found on top of the cargo when it reached Liverpool. When I tell you that the ship had been berthed alongside a German boat, you can guess how it landed up where it did. When we found it – it’s empty now, of course – one of these chambers contained sulphuric acid, the other high explosives. The membrane prevented them mixing prematurely. Here”—he inserted one finger and lifted a small metal arm—“is a spring-loaded igniter. The device that holds it back is controlled by a small rotating wheel, rather like the wheel that governs the mainspring of a watch. When you have fiddled the wheel around the requisite number of times, the device is armed and ready.”

“I follow that,” said Hall, who had been listening carefully. “But why didn’t this particular one detonate?”

“Sound mechanics, poor chemistry,” said Duprès. “The sulphuric acid mixture wasn’t strong enough to eat its way through the membrane.”

“Second objection, then,” said Hall. “How would it get onto the Bulwark? And even if you’re going to suggest that a treacherous sailor or stoker was induced to put it into the magazine, I can’t believe he’d have been clever enough – or brave enough – to open it and fiddle with the control wheel.”

“That’s the really ingenious part about it.” The major sounded as pleased and proud as though he had invented the bomb himself. “We’ll suppose that in the case of the Bulwark it was dropped from a Zeppelin. If attached to a small parachute, its descent would be leisurely. Plenty of time for the propeller, which would have been going around”—he twirled it with his finger—“to turn the wheel so that, by the time it landed on the Bulwark, it would be armed and ready. Then, as soon as the acid – a stronger mixture this time, no doubt – had eaten through the membrane, it would detonate handsomely. If a single spark reached the magazine, the ship would be destroyed.”

“Sounds a bit hit-and-miss to me,” said Hall. “How could they be sure that a single bomb would land on the ship? Or if it did, that it would end up in a place where it could do serious damage?”

“No one suggested a single bomb,” said Cooper-Key. He was provoked by this scepticism and though, as a major, considerably junior to a captain R.N., did not hesitate to show it. “Half a dozen could have been loosed and escaped detection in the dusk. However, since you find my suggestion farfetched, allow me to hand you over to my colleague. Perhaps you will find his ideas more convincing.”

The professor said, “What has been demonstrated to you is the possibility of an attack from above. I think you were wrong to dismiss it.” He looked severely at Hall, whose unconvincing attempt to look contrite was nearly too much for Luke’s self-control. “So let me offer you the alternative: an attack from below.”

He produced from his briefcase what looked like a thin stick of barley sugar.

“What I have here is a piece of caustic soda that has been coated with varnish. Before I explain how it might have been used”—a further severe look at Hall—“allow me to clear certain preliminary points. Matters of naval routine, about which you will, of course, know much more than I do. First, what armament was being carried?”

“In the Bulwark? Six and eight inch guns.”

“I’m obliged. The ammunition, then, would be in the normal two-part form. The projectile and the cordite charge would be delivered separately to the gun turret.”

“Certainly. By mechanical hoists, operating on opposite sides of the turret.”

“Just so. And if a continuous and sustained programme of firing was contemplated – in practice, or in actual battle – I imagine that there would be a number of projectiles and charges in the turret.”

“Yes. In racks, behind the guns.”

“Then, one final point: the magazine from which they came would be – I speak comparatively – a cool place.”

“Not just cool. Temperature-controlled.”

“Yes. And the turret?”

“That, of course, is quite a different matter. It’s ventilated, but after a period of firing, it does get extremely hot. If discipline allowed it, the men at the guns would work stripped to the waist.”

“Just as I visualised it,” said the professor happily. He picked up the pencil-shaped object and said, “This device can lie among TNT, quite innocuous, for months on end. But, when heat is applied, directly or indirectly, it will burst into flames – which would detonate not only the charge to which it was attached, but also the other charges around it. And if even one of the hoists leading down to the magazine happened to be open …”

He broke off. A long silence ensued. Then Hall said, speaking so unwillingly that the words seemed to be wrenched out of him, “I must confess, Professor, that I find your theory the more probable of the two. Hideously probable. A dishonest or suborned member of the crew could, I suppose, carry such a thing in his pocket. Yes? And it would be the work of a moment to insert it in one of the cordite charges – possibly when he was assisting to stack them in the magazine. Then all he would have to do is wait until that particular charge was used.”

Kell said, “We know now that the Bulwark explosion occurred when the ship was leaving Sheerness on a training course, which was to involve firing practice. The day was an unusually hot one, and if charges had been stacked ready in the turret, then trouble was very likely to occur. But don’t these facts give us a chance of locating the man concerned? Knowing what was likely to happen, wouldn’t he have made some excuse to stay off the ship? Compassionate leave, hospitalisation, a visit to the dentist …”

“Yes,” said Hall, “we can check that.”

“Also, now that you know the two possible ways of attack, you’ll be able to take steps to guard against them. If Zeppelins are overhead, don’t concentrate all your searchlights on them. Have at least one of them focused on the ship. And check all charges, both in store and before using them. That should give you a margin of safety.”

“Until the buggers think of something else,” said Hall. But he said it so softly that only Luke, who was sitting just behind him, heard it.