channels used for military purposes. The fear that spies might get hold of information about these routes was both considerable and justified. An aggressor who had succeeded in uncovering these secret channels could cause a lot of damage. As the draught of modern ships was increasing all the time, the routes had to be constantly checked. Were there alternative routes that could accommodate ships with bigger draughts? Could shallows that restricted access be dredged in secret, without the changes being marked on publicly available navigational charts?
These were the questions he would have to answer. In addition, he would also have to consider the possible threat from submarines. There was no doubt that submarines presented a completely new danger with potentially limitless consequences. But how could they be stopped? If the channels were deep enough, a submarine could penetrate to the very centre of Stockholm.
He thought back to the years between 1909 and 1912 when he had been involved in redrawing secret naval routes through the archipelago between Landsort and Västervik. In the early days he had played a junior role, but later, from the spring of 1910 onwards, he had been promoted rapidly and placed in charge of the whole operation.
Those had been happy days. In just a few years a large number of his dreams had come true.
But he then realised that he had a quite different dream. It had been unexpected, but it was that dream he now hoped to be able to turn into reality.
The dream of discovering the greatest depth of all.
CHAPTER 23
The vibrations faded away.
The ship was still.
The beast was holding its breath.
He put on his tunic again, went on deck and stood in the spot where he knew he was invisible. The gunboat Thule, with her three funnels, was drawing alongside to leeward. The sick rating had already been carried out on deck. When the Thule had completed the manoeuvre Rudin was lowered carefully down in a skilfully made sling. The smoke from the Thule's funnels swallowed him up. There was no sign of Captain Rake: the operation was being directed by Lieutenant Sundfeldt. As soon as Rudin was safely on board the gunboat, the empty sling was retrieved, the Thule backed away and then set off in a north-westerly direction towards Bråviken.
He stayed on deck and watched the Thule until she was out of sight. The smoke from her funnels blended into the scudding clouds.
Rudin was one sailor who had escaped from a terrifying trap, he thought. Swedish ships would be sunk even if Sweden managed to stay out of the war. The sailors most at risk would be in the merchant navy, but even the crews of warships would be torpedoed or blown up by mines. If Rudin did not return to his ship, he would not need to run the risk of being killed by an exploding boiler. Thanks to his inflamed appendix he might be one of the lucky sailors who would escape death.
Tobiasson-Svartman screwed up his eyes and searched for traces of the Thule. There was no sign of her now; she had disappeared into the grey coastline.
He went back to his cabin. The ship was turning back into the wind again.
CHAPTER 24
He paused in the doorway and tried to imagine what his wife was doing at this particular moment. But he could not envisage her. He had no idea what she did when she was alone in the flat. He did not like that notion. It was like holding a chart in your hand and suddenly finding that all the writing, the outlines of the islands, the areas covered by the lighthouses, the buoyage, the depth contours had all been erased.
He wanted to know what routes his wife used when he was away.
I love her, he thought. But I do not really know what love is.
He sat down at the little table and unpacked his lead. The brass gleamed. For one brief moment he had the feeling that Kristina Tacker was standing behind him, leaning over his shoulder.
'Something is going to happen,' she whispered. 'There is a point where your lead will never reach the bottom. There comes a point where everything is found wanting, my darling husband.'
PART II
The Navigable Channel
CHAPTER 25
The evening before Lars Tobiasson-Svartman started on his mission, a petty officer came to his cabin to tell him that Captain Rake wanted to give him the final instructions.
He put on his naval jacket and hurried up the slippery companionway. The crescent moon kept appearing through the