One minute later they heard the tap on the door.

* * *

‘It’s a confidence trick, sir!’

‘You have it, Wentworth. I put my hands up to it. A deceitful piece of chicanery! A dirty bit of business!’

‘The end justifies the means, then, you’d say?’

‘Don’t be tedious!’ Joe responded to her cross face with a flash of impatience. ‘This is not a debating society. This is a police force. And a national protection unit. It will take considerable nerve and a degree of low cunning to pull it off. You, I observe, are not short of either, so stay with the stroke I set, will you? We’re anticipating no less than the removal — the permanent removal, one hopes — of this menace to the lives of the prince and the rest of the royal family. When it’s removed, gone abroad, they’ll be able to go about their daily business once more without the constant fear of assassination.’

‘You say “it”, sir.’ Lily spoke hesitantly. ‘We’re talking about “she” — a strong-minded woman who will object to being manipulated. She may refuse to accept a suggestion that she simply leave the country.’

‘I would expect so. And that’s why we have to make her an offer that is irresistible to her. One that will give more satisfaction than sticking a knife in HRH or whatever she has planned for him next time. We have to thank some ancient Greek for an old military proverb: If you wish to get rid of your enemy, build him a golden bridge to flee across.

‘Aristides’ advice to Themistocles, I believe, sir,’ Bacchus chipped in. ‘Concerning the Persian retreat back across the Dardanelles.’

‘Thank you, Bacchus. I believe you’re right. And we’re going to take it again. It’s exactly what we’re going to do. With the utmost politesse we’re going to show our enemy to the border and offer a passage out. The golden bridge in question is a first-class berth on a luxury liner — the Hirondelle did you say, Bacchus?’