Since he was smiling, I assumed he hadn’t meant the question to come off like a challenge. I was wary all the same. Walking into a group who’d been diving together for a number of years could be intimidating. It was the same in academia and in countless museums and university archives all around the world. You had to prove yourself in order to gain acceptance and even when you did, there was always someone waiting to cast judgement or find out where your alliances lay.

‘If we’re talking internationally,’ I said, ‘I have a soft spot for the Great Blue Hole in Belize. I did a pretty amazing dive there a few years ago at thirty-five metres. If we’re talking about Australia, you can’t beat the Reef.’

His eyes glinted appreciatively. ‘The Great Barrier Reef? I’ve always wanted to dive there.’

‘Well, you’d better go soon. They say the coral bleaching’s only going to get worse. In less than fifty years, the whole reef will be gone. It’s the same everywhere. Warmer oceans killing off the marine wildlife, coastal erosion, algae blooms. You must have noticed the changes here.’

Nico’s smile faded. ‘It’s true. We’ve been warning everyone who’d listen for years. But nobody really takes us seriously. Maybe they will now, assuming we’ve found something special.’

‘Have you been back down?’ I said.

Bram shook his head. ‘Weather’s too unpredictable. You remember what autumn’s like here; the wind has teeth. We get more storms now, too. Worse than before. One minute it’s sunny, the next you’re getting pelted with hailstones as big as your fist.’

He squinted up at the blue sky, as if expecting the heavens to open up and drench us all.

‘We should get moving,’ said Nico. ‘Doctor Baaker’s probably feeling pretty washed out after her flight. And I promised Anneke I’d be back soon.’

His accent was a little more Frisian than the others. The Frisian accent always sounded to me like a curious cross between English and Scottish, harder than English but softer than German, the lack of fricative consonants like sea glass smoothed by the tide. Mainlanders often struggled to understand the dialect.

‘It’s just Jo,’ I said. ‘We don’t go in for official titles much in Australia. And I’m not tired. I’d like to see the artefacts as soon as possible. Textiles are extremely fragile and sudden change in temperature or humidity can damage them. Liam will take over when he arrives tomorrow. He’s much better at the conservation stuff than I am.’

‘Liam’s your colleague?’ Nico asked.