‘Speak to them in their own language,’ he continued coolly.  ’Tell them I’ll blow them out of the water if they try any more tricks of that sort.’

Ken’s announcement was followed by dead silence aboard the steamer.  Then a second officer appeared at the rail.  He had both hands up.

‘We surrender,’ he said.

‘’Bout time, too,’ growled the big bluejacket.

Strang repeated his former orders, and this time they were obeyed without hesitation.  Ken’s heart beat thickly as he watched the prisoners hurrying into the boat which had been lowered from her davits to a level with the deck.

‘Do you see your father yet?’ Strang asked.

‘Not yet, sir,’ Ken answered, with his eyes fixed on the fast-filling boat.

‘Sixteen—­seventeen—­eighteen,’ he counted mechanically.  Suddenly a slight cry escaped his lips, and he started forward.

‘Father!’ he shouted loudly.

An upright man with keen blue eyes, a man of about fifty, but whose hair and moustache were almost white, was in the act of getting to the boat.  At Ken’s cry, he started violently, stopped short and stared incredulously in the direction of the sound.

‘Father!’ shouted Ken again.

‘You, Ken?’ The tone was one of utter amazement.

‘It’s me all right, dad,’ Ken answered in a voice which shook a little in spite of himself.

Before their eyes the other seemed to shake off ten years of age.  He sprang into the boat as lightly as a boy.  Three more followed, making twenty-two in all.  Then the blocks creaked, and the boat was rapidly lowered to the water.

Oars began to ply vigorously, and she shot across the intervening space, and a minute later was alongside the submarine.

‘You must wait there, please, gentlemen,’ said Strang courteously.  ’I have to deal with the troops at once.  Keep well astern.’

Ken was aching to greet his father, but there was plenty for him to do for the moment.  He had to translate the commander’s orders, which were that all those aboard the steamer should get away at once in the boats.  He gave them twenty minutes for the operation.

They were the longest twenty minutes Ken every knew, but they were over at last.  The crowded boats pulled slowly away in a northerly direction, the big steamer floated empty and helpless.

‘Do we board her, sir?’ asked young Hotham of Strang.

’Yes, I’ll save my torpedoes while I can.  Put a good charge of gun-cotton in her hold.  Quick as you can, Hotham.  We may have a destroyer down on us any minute.  You may be sure they had plenty of time to use their wireless.’

He turned to the boatful of released prisoners.  They were of every sort, young and old—­French, English, with even one or two Russians and Belgians.

‘Gentlemen,’ he said briefly, ’I can’t ask you all aboard.  The reason is obvious.  In a submarine there is only room for a certain number, and I am already three beyond my proper complement.  The question is, what I am to do with you for your safety, and I should be obliged if two of you would come aboard to discuss matters with me.  One whom I will specially ask is Captain Carrington.’