Ken’s face fell.  In his delight at meeting his father again, he had quite forgotten the difficulties still before them.

‘But—­but I thought that Lieutenant Strang had a plan,’ he stammered.  ‘He’s towing the boat somewhere.’

His father nodded.

’Yes, I suppose it need be no secret from you.  He is taking us, or trying to take us, to a certain cave on the south shore of the sea.  It is one of the hidden petrol bases which are supplied by friendly Armenians.  But, even if we get there safely, there is always the risk of discovery by the enemy, as well as difficulties of provisioning so many of us.  And we may not even get there.  Supposing that an enemy ship appears in chase, and the submarine has to submerge, what then?’

Ken gazed at his father blankly.  Before he could speak again a sharp hail came from the look-out in the conning tower.

‘Ship in sight, sir!’

CHAPTER XVII

THE BOARDING PARTY

Ken and his father were both on their feet in an instant.  While they had been talking it had turned misty.  It was only a haze, but it blurred the horizon so that at first they could not see the vessel.

But presently Ken pointed.

‘There she is.  Do you see, dad?’

Captain Carrington nodded.

’I see her, Ken, but my eyes are not what they were.  I can’t tell what she is.’

At this moment Lieutenant Strang stepped up to them.

‘It’s just as I was afraid, sir,’ he said quietly.  ’There appears to be something after us.  It’s so thick I can hardly make out what she is yet, but in any case it’s precious awkward.’

‘Very awkward indeed,’ admitted Captain Carrington.  ’Alone, you would be all right, for you could submerge of course, but if so you leave us prisoners to be picked up again.  Still, of course, there is no choice.  You must not risk your ship.’

Strang bit his lip.  He knew that Captain Carrington was right.  But it went bitterly against the grain to abandon the people whom he had rescued with so much trouble.  As for Ken, the idea of losing his father again just after he had found him sent his spirits down to zero.

After a moment’s thought, Strang spoke again.  ’I might leave the boat, sir, and tackle this fellow, whoever he is.  It’s on the cards I might sink him and come back again and pick you up.’

‘That might be worth trying,’ answered Captain Carrington.  And he spoke as calmly as if the upshot was of absolutely no consequence to him whatever.

Ken, who had been staring hard at the approaching craft, turned quickly to the commander.

‘Couldn’t you capture her, sir?’ he said eagerly.

Strang stared as if he thought that Ken had suddenly taken leave of his senses.

‘Capture her?’ he repeated.

’Yes, sir.  Then you could put all the prisoners aboard her, and they could find their own way to the hiding place.  And Horan and myself, too, perhaps.’