‘Let’s hope it waits until we’ve finished,’ said Nina as Cheng zoomed in. She was impressed by the speed of his satellite link; she had used similar technology in the past, but it always felt like going back to the days of dial-up modems compared to the unthinkingly accepted transparency of a Wi-Fi connection. This was practically broadband speed, though, even in the middle of the ocean. Technology kept advancing behind her back.

Imka regarded the icy peaks, then, frowning slightly, asked Cheng: ‘Can you show me the picture Arnold sent when he first found D43?’

She had given him access to a cloud folder of files regarding the iceberg survey; it only took him seconds to bring up the picture. Nina also peered at the berg ahead before returning her gaze to the laptop. ‘It’s different.’

The South African nodded. ‘The topography has completely changed. This formation here,’ she pointed out a squared-off peak in the four-month-old photograph, ‘has gone.’

‘Wim said something . . .’ Nina tried to remember the Dutchman’s words. ‘Something about everything turning over. That could be what he meant.’

‘These things do roll,’ said Tate. ‘And you don’t want to be anywhere near them when they do. You could be hundreds of metres clear and still have part of the berg come up under you like a bloody whale.’ He stared at the distant iceberg. ‘That looks like clean ice, no snow on it. It’s been underwater. I’d say the whole thing flipped over.’

Imka looked stricken. ‘If Arnold’s ship was inside the iceberg when that happened . . .’

‘There’s still a chance,’ Nina assured her, though she was far from confident herself.

The Torrox sailed on. Vorster surveyed the growing berg through binoculars. ‘I can’t see any caves big enough to take a ship.’

‘Could be on the other side,’ said Eddie. ‘Anything on the radar?’

The iceberg’s flank displayed as a crinkled, hazy line, smaller echoes dotted before it. ‘The S-band radar should show a ship inside the ice, as long as it’s not too deep,’ said Tate. ‘Or half a K underwater, which it might be after the thing rolled.’

The addendum was not something Imka wanted to hear. Nina gave the younger woman another look of reassurance.

Tate brought the Torrox into a clockwise orbit around the iceberg. Even though they were clear of the larger hunks that had calved from D43, growlers still occasionally clunked against the hull. Cheng flinched with every impact.

‘You okay?’ Nina asked.

‘Yes, yes,’ he said, looking anything but. ‘I . . . don’t like being on a ship.’

Eddie chuckled. ‘You wait until now to tell us?’

‘It makes me feel sick. I don’t like high places either.’

‘You’ll be fine,’ said Nina. ‘You haven’t thrown up so far, after all.’ A mournful look from Cheng. ‘Oh. You have?’

‘In my cabin,’ he admitted, a little shamefaced.