‘Rich Bangladeshis typically travel to Singapore or Bangkok for IVF,’ murmured Hessa. ‘In fact, the wealthiest would travel abroad for most medical issues. They don’t have much faith in Dhaka’s hospitals.’

‘All you needed here were the basic requirements for the frozen embryo transfers,’ said Casey. ‘Presumably Greystone could coordinate the egg extraction and fertilisation anywhere in the world. They just had to ensure the carrier woman was at the right point in her cycle.’

They said goodbye to the women, Romida giving Casey a sudden bright grin.

On the way back to the hotel, Casey leaned back in the tuk-tuk. ‘We still don’t know the scale of it,’ she said. ‘Were those women the only ones that Greystone’s lot has seized? Or are there other sites, scattered around the country? How much is he pulling in from this scheme?’

‘Emily would be able to tell us exact prices,’ said Hessa. ‘Surrogacy varies from country to country. In the US, it’s about $150,000 all in. It’s less in Kenya. In the Ukraine, it’s more like $40,000. Some countries have more delays. The clinics vary too. Some clinics offer several rounds; others offer certain guarantees. Your money back if you don’t get a baby. Then there are the legal costs for getting a baby back to the UK – or wherever. They vary dramatically too. Given that Greystone seems to be able to get the kids back to England fairly straightforwardly without any waiting lists, he’s probably able to charge quite a premium even though he’s operating under the radar. Let’s say $25,000 per child.’

‘God.’ Casey put her head in her hands. ‘The mathematics are barbaric.’

‘And how many a year?’ Hessa persisted. ‘If there were fifteen women at the shipyard when we got there . . . There could be, say, twenty babies a year.’

‘That’s half a million dollars a year from the shipyard women alone,’ calculated Casey. ‘And Greystone has access to an endless stream of desperate women on Harley Street. There could be other sites in Bangladesh, or anywhere else, too.’

‘There may even be word of mouth back in London,’ said Hessa. ‘Although, as the Burton-Smiths show, if you don’t want to know, they certainly won’t spell it out to you.’

‘He would be making millions every year,’ said Casey. ‘How old was Vivienne Hargreaves’s son? Three? It could have been running for years.’

‘I wonder what happened to the Rohingya women after they gave birth,’ said Hessa.

‘I suppose they would just have another baby,’ said Casey. ‘Or . . .’

Hessa turned her face away.

‘I wonder if one of the women from the shipyard ended up in the garment factory?’ Casey speculated. ‘And that’s how she managed to get the message into the skirt Cressida found.’

‘Maybe,’ muttered Hessa. ‘Maybe she wasn’t able to get pregnant, so they shunted her out to the factories. I suppose we’ll never be able to find out.’