They found her body in the wrong country’s river. The officers grimaced at the stench as they fished her out, eelgrass wrapped around her like the water wanted to keep her.

The sergeant’s tongue curled around rusty English. ‘The maps you have said she is having,’ he grumbled, not unkindly, ‘my man found them some space back: in the tunnels.’

‘In the sewer?’ she asked, her face quite still.

‘Well, the sewer . . . Actually the water is different, it is all a mix down there, like a bee hive. Like the movie with the singer. The sewers meet it but so do other things.‘ He tipped his hand from side to side. ‘It is a tourist attraction, they make sure it’s clean or at least that it smells well. When has your friend disappeared?’

She remembered, not much more than eight hours ago, waving to that bright, grin-faced woman from the airport security gate, scarf and pale hair mounded on her like a sundae. Here was the last thing she’d said to Margaret: ‘Don't eat my cat.’ And Margaret had rolled her eyes and disappeared from view.

The flight had been sleepless and exhausting in that numbing way long flights mostly are. The police had called her before she could collect her luggage.

They were waiting for her at international arrivals and led her to a patrol car. There had been an uncanniness about it until now, a sense that Margaret would be joking about this strange moment with her later, but now her footsteps had vanished beneath the rush of the river and the sky seemed too bright and too grey.

Among the gurneys and rows of metal drawers the air was very cool and still as they lifted the plastic to reveal the body's face. She shook her head, she shook her head. She opened her mouth and a tremulous mumble escaped it which she later recognised as a failure to say her sister's name. The officers and the paramedics watched. She swallowed, brushed imaginary hair out of her eyes and looked into their faces.

‘That’s not possible,’ she said again. ‘Her flight wasn't for weeks.’

Then she was sitting in her rental car, knuckles white on the scrawl-covered maps they’d let her keep, having just realised that she had been crying for some time. She turned the ignition off.

‘You asshole,’ she breathed, ‘you miserable lunatic. You were right.’ Her voice rasped so harshly she barely recognised it. She tried to clear her throat but something was stuck there. Her fingers dug into the maps of the mountains and the tunnels, those guilty topographies. ‘You found it.’