‘"Heave to, or I’ll sink you,” that means,’ observed Ken’s friend.

The only response was a thicker hail of bullets.  But the low deck of G2, flying onwards as she was at about twenty-two land miles an hour, made a poor target, and the Turks failed to do any damage beyond knocking a little paint off.

’Confound ’em!’ growled Strang.  ’They haven’t got sense enough to come in out of the rain.  Give ’em a shell, Watson.’

The long gray 12-pounder was ready.  Her vicious-looking muzzle swung round.  There was a ringing bang, and the shell, small but charged with deadly lyddite, spun away on its errand.

[Illustration:  ‘A black-browed officer came to the rail.’]

Ken, watching eagerly, saw a bright flash light the side of the steamer, close under her stern, and as a cloud of smoke floated up, the crash of the explosion came back to his ears.

The big steamer staggered and yawed right out of her course.

‘Capital!’ said Strang with strong approval.  ’That’s hashed her steering.  Signal ’em to heave to, or the next will be in their engine-room.’

There were a few more scattering rifle shots, but the officers on the transport soon stopped that.  The transport herself, with her rudder in rags, was out of all control.  Her engines were stopped, and she lay sullenly waiting for her saucy little enemy.

Strang gave a sigh of relief.

‘Glad they had the sense to shut up,’ he said to Ken.  ’If they’d gone on shooting I should have had to sock it into them, and I didn’t want to break my promise to your old Pacha.’

The submarine, smartly handled as usual, glided up close under the tall side of the transport, and Strang hailed her in French.

A black-browed officer, with angry eyes, came to the rail, and answered in the same language.

‘You have British and French prisoners aboard,’ said Strang sharply.  ’You will be good enough to put them all into a boat and send them across.’

‘And if I refuse?’ retorted the other.

‘I shall shell you until you think better of it,’ was the calm reply.

The other bit his lips.  ‘Very well,’ he said sullenly.  ‘I have no choice.’

‘Look out for treachery, sir,’ said Ken in a low voice.  ’That man means mischief, I believe.’

‘He is an ugly looking beggar.  But what can he do?’

The words were hardly out of his mouth before the black-browed officer flung up his arm, with a pistol gripped in his fist, and fired straight at Commander Strang’s head.

Quick as he was, Ken was quicker.  As the man’s arm came up, so did Ken’s, and seizing Strang by the wrist, he jerked him back.

Before the man could fire a second time, one of the bluejackets had raised his rifle and shot him through the body.

‘Thank you, Carrington,’ said the commander, glancing at the gray splash of lead on the deck, just where he had been standing the previous moment, ’You were right, and I was wrong.