She briefly opened a shoulder bag to reveal banknotes inside. ‘Twenty-five thousand euros, as agreed. Did you get the money from Hui?’

‘Not all of it. Only fifteen thousand,’ he lied, hoping she might make up the difference. ‘I wanted all fifty.’

‘That is not my problem. You are fortunate I am willing to pay you at all.’ Her voice was quiet and even, but there was an angry edge to it. ‘Hui and Wilde were going to leave without the key because you doubled the price.’

‘How did— You bugged my flat?’ he yelped in realisation.

‘Keep your voice down. And yes, of course we did. This is very important to us. Your greed could have ruined everything.’

‘So could me being shot!’ he snapped. ‘I was thrown out of a window – your bugs didn’t stop that, did they? And you have no idea who those men are?’

‘No,’ said Wu, ‘but we will find out.’ No doubt, just a statement of fact.

‘Well, I wish you luck,’ said the German impatiently, ‘but now it is time for me to go. My money?’

She looked around. To their left, apartment buildings overlooked the park. The grassy area to the right was darker, trees blocking most of the nearby illumination. ‘Over there.’

Krämer checked the shadows, but saw nobody lurking in wait. He angled with her off the path. They circled behind a tree, out of the light. ‘Okay. The money.’

She slipped the bag from her shoulder, supporting it from beneath as she used her other hand to open it. ‘Here.’

Krämer stepped closer. Even in the darkness, the bundles of clean, new banknotes stood out clearly. ‘Good. I will—’

Her supporting arm suddenly moved – and a slender carbon-fibre blade sank deep into his stomach.

Krämer gasped, trying to draw back, but a fire spread through his body, incinerating his nerves and paralysing his muscles. ‘You, you . . .’ was all he managed to whisper before the hideous sensation reached his mouth. He convulsed, a strangled rasp forcing its way from his throat, then crumpled to the ground.

Wu gazed at him with no more emotion than if she had crushed a bug. A glance at the apartment buildings to make sure she was not being observed, then she crouched, checking his pulse.

She found the beat immediately, racing as terrified adrenalin flooded his system, but already beginning to slow. She kept her hand in place, feeling it become weaker, slower still.

And finally stop.

She searched him for Hui Cheng’s money. He had lied; there were ten thousand euros more than he’d claimed. Wu was not surprised. She also took his phone, to conceal the electronic trail linking them. The poison on the knife was undetectable in a standard autopsy; with nothing left on his body to raise the eyebrows of the police, it would seem like nothing more than a mugging gone wrong, a down-on-his-luck merchant sailor taking a wrong turn.