‘Will report your return,’ he spelt out.

A pause followed. Then a figure was seen to clamber to a position of vantage on the submarine’s standard and there was a flash of red and yellow bunting.

‘What does he say?’ asked Raymond, when the message came to an end.

The boy saluted. ‘“123” to Zero, sir, “Your signal not understood. Will report sinking of Zero by torpedo on my arrival at base.” Eleven twenty-five, code time, sir.’

‘What did I tell you, Burton?’ laughed the captain. ‘It’s no good trying to get to windward of Raymond. He’s always undefeated to the end.’

‘Precocity, I call it,’ said the other, who was bitterly grieved at the downfall of Jenkins’s attempt to score off the wily ‘hate-boat.’

The signal boy turned his back sharply and busied himself with his flags, while he hid a smile behind a grimy hand. He was used to this sort of chaff among the gods, but experience had taught him that it was not well to display too keen a sense of humour on these occasions.

Three minutes later, with her engines at a reduced speed, the Zero took the gate and sped on up the harbour. As she passed the big ships the boy pounced on an answering pendant, ran it up to the yard-arm, and glued his eye to the telescope.

Parentis to Zero,’ he spelt out. ‘Moorings alongside Parentis occupied. Anchor in No. 4 berth.’

‘Down answer,’ he added, and the pendant fluttered to the deck.