‘Keep it short, Wentworth. Every single letter is a work of art for our chap, remember.’

She finished with a rush. If I thought a command would influence you, I would say: ‘Come! At once!’ But I now beg you, dearest Anna, to come to me and complete my happiness. And here in this delightful place I know I have the means to make yours. Leave that drab and violent continent to its death-throes and sail into the sunshine! We are waiting with our arms outstretched! Silent, upon a peak — in Darien! Your devoted friend, T.

Joe snatched it from her the moment she had blotted it. ‘Good!’ he said. ‘That would get me rushing for the boat!’ And, thoughtfully, ‘That’s a neat bit about her brother. It wasn’t in my briefing. Is this a case of “Miss thinks she knows best”? I believe it is. But does it add up? You don’t say that he’s alive or that he’s dead. Just enough to sow doubt. There are rumours about — strong ones, especially in Romanov circles — that the whole family was spirited away. And the promise of a warm welcome over the ocean may well be ultimately persuasive when our girl considers the alternative we have on offer for her here in London.’

He took a deep breath and came to a decision. ‘Yes! Wentworth, we’ll go along with your scenario. If she’s convinced by this, Anna Petrovna’s reason to stay on plotting mischief over here is removed at a stroke. If only … What do you say to appropriating one of those lockets? There’s one containing a wisp of the Tsarevich’s hair.’

‘No, sir. That would be overplaying it. She wouldn’t send something so precious across in the post or even the diplomatic bag. Wouldn’t feel she needed to. This is Her Imperial Highness writing. Enough for anyone to be told, in her handwriting of course, that she survives. She wouldn’t expect to have to supply proof or answer questions. I think you’re right — it should be understated … no one’s impressed by a gilded lily. We should keep it … tantalizing.’

‘This reference to the French master … Assuming too much, do you think?’

‘Take a look at the photograph again. Our dark-haired beauty is casting what I’d interpret as a decidedly languishing look at the tutor. Whatever she has on her mind, it’s not French grammar. And it’s a pretty safe bet anyway. There weren’t many men under forty and over fourteen in the lives of these girls at this point and Pierre Gilliard was a well-set-up fellow. Every girl falls in love with her French master. Done it myself.’

‘It’s a bit of a risk. We’ll have to see what Bacchus thinks of it. I think we have time for a little rehearsal.’

Bacchus read the sheet and then read it again. He opened his mouth to comment and closed it. Finally, he said, ‘This will do. I note the change of plan. In the Wentworth version the Tsarevich very likely survives also. Another prince saved. That’s two in a week. Well done, miss! But what’s this here about Darien? Will she be familiar with Keats?’

‘I think everyone knows this line … the poet’s vision of the conquistadors standing on a height above the bay, rendered speechless by their first sight of the Pacific Ocean. I noticed that the girls liked to scatter literary references about.’