But as the Devonian's radio was unable to pick up the BBC, everyone on board went about their business as if it was a normal day.

Harry was still thinking about Emma when the first one shot past the bow. He wasn't sure what he should do. He was loath to disturb the captain during dinner for fear of being reprimanded for wasting his time. Harry was wide awake when he saw the second one, and this time he had no doubt what it was. Harry watched as the long, slender, shiny object slithered below the surface towards the bow of the ship. He instinctively swung the wheel to starboard but the ship veered to port. It wasn't quite what he'd intended, but the mistake gave him enough time to raise the alarm because the object shot past the bow, missing the ship by several yards.

This time he didn't hesitate and jammed the palm of his hand on the klaxon, which immediately emitted a loud blast. Moments later Mr Bradshaw appeared on deck and began racing towards the bridge, closely followed by the captain, pulling on his jacket.

One by one, the rest of the crew came rushing out of the bowels of the ship and headed straight for their stations, assuming it must be an unscheduled fire drill.

'What's the problem, Mr Clifton?' asked Captain Havens calmly as he stepped on to the bridge.

'I think I saw a torpedo, sir, but as I've never seen one before, I can't be sure.'

'Could it have been a dolphin enjoying our leftovers?' suggested the captain.

'No, sir, it wasn't a dolphin.'

'I've never seen a torpedo either,' Havens admitted as he took over the wheel. 'Which direction was it coming from?'

'Nor'-nor'-east.'

'Mr Bradshaw,' said the captain, 'all crew to emergency stations and prepare to lower the lifeboats on my command.'

'Aye aye, sir,' said Bradshaw, who slid down the railings on to the deck and immediately began to organize the crew.

'Mr Clifton, keep your eyes peeled and tell me the moment you spot anything.'

Harry grabbed the binoculars and began a slow sweep of the ocean. At the same time, the captain bellowed down the voicepipe, 'All engines reverse, Mr Patterson, all engines reverse, and stand by for further orders.'

'Aye aye, sir,' said a startled chief engineer, who hadn't heard that order since 1918.

'Another one,' said Harry. 'Nor'-nor'-east, coming directly towards us.'

'I see it,' said the captain. He swung the wheel to the left and the torpedo missed them by only a few feet. He knew he was unlikely to pull off that trick again.

'You were right, Mr Clifton. That wasn't a dolphin,' said Havens matter-of-factly. Under his breath he added, 'We must be at war. The enemy has torpedoes, and all I've got is a hundred and forty-four Raleigh bicycles, a few sacks of potatoes and some cotton dresses.' Harry kept his eyes peeled.

The captain remained so calm that Harry felt almost no sense of danger. 'Number four coming directly at us, sir,' he said. 'Nor'-nor'-east again.'

Havens gamely tried to manoeuvre the old lady one more time, but she didn't respond quickly enough to his unwelcome advances and the torpedo ripped into the ship's bow. A few minutes later Mr Patterson reported that a fire had broken out below the waterline and that his men were finding it impossible to douse the flames with the ship's primitive foam hoses. The captain didn't need to be told that he was facing a hopeless task.

'Mr Bradshaw, prepare to abandon ship. All crew to stand by the lifeboats and await further orders.'

'Aye aye, sir,' shouted Bradshaw from the deck.

Havens bellowed down the voicepipe. 'Mr Patterson, get yourself and your men out of there immediately, and I mean immediately, and report to the lifeboats.'

'We're on our way, skipper.'

'Another one, sir,' said Harry. 'Nor'-nor'-west, heading towards the starboard side, amidships.'

The captain swung the wheel once again, but he knew this time he would not be able to ride the punch. Seconds later, the torpedo ripped into the ship, which began to list to one side.

'Abandon ship!' shouted Havens, reaching for the tannoy. 'Abandon ship!' he repeated several times, before he turned to Harry who was still scanning the sea through his binoculars.

'Make your way to the nearest lifeboat, Mr Clifton, and sharpish. There's no point in anyone remaining on the bridge.'

'Aye aye, sir,' said Harry.

'Captain,' came a voice from the engine room, 'number four hold is jammed. I'm trapped below deck along with five of my men.'

'We're on our way, Mr Patterson. We'll have you out of there in no time. Change of plan, Mr Clifton. Follow me.' The captain shot down the stairs, his feet barely touching the steps, with Harry just inches behind him.

'Mr Bradshaw,' shouted the captain as he dodged in and out of the oil-fed, lapping flames, which had reached the upper deck, 'get the men into the lifeboats sharpish and abandon ship.'

'Aye aye, sir,' said Bradshaw, who was clinging on to the ship's railings.

'I need an oar. And make sure you have one lifeboat on standby ready to take Mr Patterson and his men from the boiler room.'

Bradshaw grabbed an oar from one of the lifeboats and, with the help of another seaman, managed to pass it to the captain. Harry and the skipper took one end each and stumbled along the deck towards number four hold. Harry was puzzled what use an oar could possibly be against torpedoes, but this wasn't the time to be asking questions.

The captain charged on, past the Chinaman, who was on his knees, head bowed, praying to his God.

'Get yourself into the lifeboat, now, you stupid bugger!' shouted Havens. Mr Lu rose unsteadily to his feet, but didn't move. As Harry staggered past, he shoved the man in the direction of the third officer, causing Mr Lu to topple forwards and almost fall into Mr Bradshaw's arms.

When the captain reached the hatch above number four hold, he wedged the thin end of the oar into an arched hook, jumped up and threw all his weight on to the blade. Harry quickly joined him and together they managed to lever up the massive iron plate until there was a gap of about a foot.

'You pull the men out, Mr Clifton, while I try to keep the hatch open,' said Havens, as two hands appeared through the gap.

Harry let go of the oar, fell to his knees and crawled towards the open hatch. As he grabbed the man's shoulders, a wave of water swept over him and into the hold. He yanked the seaman out and shouted at him to report straight to the lifeboats. The second man was more agile and managed to pull himself out without Harry's assistance, while the third was in such a blind panic that he shot through the hole and banged his head on the hatch lid before staggering off after his shipmates. The next two followed in quick succession and scrambled on their hands and knees in the direction of the last remaining lifeboat. Harry waited for the chief engineer to appear, but there was no sign of him. The ship lurched further over and Harry had to cling to the deck to stop himself falling head-first into the hold.

He peered down into the darkness and spotted an outstretched hand. He put his head through the hole and leaned down as far as he could without falling in, but couldn't quite reach the second officer's fingers. Mr Patterson tried several times to jump up, but with each attempt his efforts were hampered as more water poured in on top of him. Captain Havens could see what the problem was but couldn't come to their assistance, because if he let go of the oar the hatch lid would come crashing down on Harry.