The sun was high when they set off in Tim’s ancient car, driving fast through the spiky lines of the sisal plantations until the tarmac gave way to a rutted, sandy surface.

‘I feel rather mean, not spending New Year’s Eve with our parents,’ Sarah said. ‘It’s going to be full of nostalgia. But I agree with Tim and Piet – we should be looking to the future, not dwelling on the past.’

‘Talking of the past, I’m sorry about Mother last night,’ Camilla’s face was calm, but her voice sounded unsteady.

‘Forget it. Most parents have some things they don’t want to discuss,’ Piet said. ‘Pa wouldn’t say a word when we got back to the beach house, and Ma told us never to bring up last night’s incident again.’

‘But maybe it’s something we ought to know about,’ Hannah said.

‘No. We should respect his wish. It sounds like he had a run in with the British government, and it’s been recorded somewhere. But he’s not the only farmer who’s been in that position. Anyway, our friendship isn’t based on our parents’ lives – it’s our own thing.’

‘I suppose you’re right,’ Hannah said, doubtfully. ‘They’re a different generation and we can’t spend our time thinking about what they did or didn’t do.’

She was prevented from saying more as the car hit the dirt road with a spine-juddering leap. They opened the windows and sang at the tops of their voices. Further mention of the previous evening was, by tacit agreement, taboo. At Mida Creek they skirted the tidal mudflats, bright with birds and ringed by the mangrove trees that flourished in the brown water. There was a slight breeze and the air smelled of salt as they turned off the main road to reach the ruined city of Gedi.

‘We can wander around first, and then have our picnic at the Sultan’s Palace,’ said Tim. ‘And when we’ve had enough of ghosts and ruins, we’ll head down to the beach at Watamu. That sound OK?’

‘Just as long as we’re out of here by nightfall,’ Sarah said

‘Ah yes. A haunted city isn’t the place for our Sarah after dark!’ Camilla was teasing as Tim turned down the narrow track. ‘I hear there are ghosts all over the place.’

‘It’s strange that it never appeared on the old Arab charts,’ Tim said. ‘A thriving city, but their closest neighbours were completely unaware of it. And no one knows to this day whether they were killed off by malaria, or hostile tribes, or if they just abandoned the place. Watch out for snakes and siafu, by the way – you don’t want to walk into a line of those ants.’