Bespectacled and dressed in a laboratory coat, he arrived a few minutes later and greeted them warmly before leading them down a narrow corridor. ‘Apologies for my tardiness,’ he said. He opened a door and led them on to the factory floor. It looked like an illegal version of Willy Wonka’s factory. To the right of them, vats of red liquid bubbled away like hot blood. Factory workers dressed in boiler suits and hairnets dropped dry fabric into the large pots and stirred them with broom-handle-like wooden sticks. Liquid from several of the vats was being siphoned off, and evaporated through a complicated system of glass pipes to leave behind a solid substance.

‘All these scarves are to be sold in Mumbai Mart,’ the owner said. ‘They’re all pure silk. Take a look.’ He handed Jia the scarf with the flourish of a souk trader.

She passed the fabric through her hands; it felt like an ordinary dupatta.

‘Thank you for showing us around, Safaid Posh.’

‘No problem, and please, no one calls me that any more. Everyone translates it to “White Coat”. It’s a bit naff but it’s easier,’ he said, and then quickly moved on. ‘The scarves are soaked in a solution of the product at our factories by the border of Afghanistan, dried and then imported here as ordinary scarves. This plant is where we reconstitute the product.’

‘The product?’ asked Idris.

‘Monkey water,’ White Coat said. Idris looked at him expectantly, waiting for him to explain. For the son of a dealer, his drug terminology was limited. ‘You know, liquid heroin. We sell it by the syringe or in a dropper bottle. Costs a bit more to us but our contact at the needle exchange helps us keep prices low, and I figured the cleaner we keep our users, the bigger our market.’

Although both had known about this side of the city’s industry for years, they had not seen the operation first-hand until now. They were impressed and told White Coat as much. ‘That means so much to me,’ he said. ‘Please, come into my office. I’ve ordered tea.’

They agreed to his hospitality and took a seat in the sparsely decorated but highly organised office. Filing cabinets lined one side of the room. Planning charts, delivery dates and detailed drawings of operations lay across the desk.

‘Do you worry about keeping so many records?’ asked Idris.

‘No. Everything is encoded. Besides, this is just delivery dates for our halal operation. A large percentage of our business is just ordinary fabric retail,’ said White Coat. A young woman in a white headscarf came in carrying a tray with a cafetière and glass cups. She placed the tray on the desk in front of White Coat. He began pouring kava into small cups. ‘Remember Nighat? The girl you set me up with at school?’ he said to Idris.