‘It’s awfully strange to think I’ll probably never see it again,’ she said, pushing back the strands of hair the wind was blowing across her face.

‘Never say never,’ said Lil. ‘After all, in our line of work, who knows where we might end up next? Perhaps we’ll come back to St Petersburg again some day.’

‘Perhaps we will,’ said Sophie. ‘It’s not a place I ever thought I’d visit – but I must say, I’m awfully glad I did.’

‘It’s all been rather unexpected, hasn’t it?’ Lil agreed. ‘I mean, who’d have thought I’d travel across Europe with Carruthers – or especially that we’d both end up joining the circus!’

Sophie laughed. ‘But now the adventure is over and we can go home.’

‘Oh, I’m not sure the adventure is ever really over,’ said Lil. ‘But yes – home. Just think of all the things we can do. Sleep in our own beds! Eat a jolly good dinner!’

‘Go to Lyons Corner House for tea and buns.’

‘Well, of course. That goes without saying.’

‘But first we’ll go to the Bureau. We’ve got work to do.’

‘We need to tell the Chief what’s what – and use the spyglass to examine those paintings – but what’s more, we need to find out the truth about the double agent at the Bureau, who’s working for the Fraternitas.’

‘I’ll tell you what else,’ said Sophie. ‘I want to investigate Mr Gold. Do you really think there’s any way he could have a connection to Roberta Russell?’

But Lil didn’t answer. Watching the swirling water had suddenly reminded her of standing on the deck of the boat to Ostend – and what she’d been thinking about then – and her mouth curved into a smile. ‘Of course, before we go to the Bureau, we should go to Taylor & Rose and see the others,’ she added more slowly. ‘Everyone will be awfully glad to see you home safe, Sophie. And it will be so wonderful to see them too.’

Sophie looked at her sharply. Lil’s face had taken on an uncharacteristically dreamy look – and could that be a faint blush on her cheeks? ‘Anyone in particular that it will be so wonderful to see?’ she asked archly, raising her eyebrows.

Lil blushed harder. ‘Oh no,’ she said, with a little laugh. ‘You know, just everyone.’

‘Everyone. Ah yes, I see,’ said Sophie, with a smile.

The two friends stood in silence after that, feeling the wind against their cheeks. Here, the water was as smooth as glass, mirroring the sky arching overhead. It was hard to tell where the water ended and where the sky began, thought Sophie, staring out across the pale blue, back towards the city which was now little more than a shimmer of pink and turquoise and gold on the horizon. Together, they stood and watched as St Petersburg vanished away from them, twinkling in the mist like something from an already half-forgotten dream.