They were waiting for me in the throne room, and this time I could see it was a throne room, the potted mangrove sheltering the sacred World of Leather executive armchair. There sat Mama Thames, resplendent in her Austrian lace and a headdress of blue and white Portuguese beads. Behind her were arrayed her attendants in batik lappas and headscarves and on her left and right hands, forming an aisle down which I had to walk, stood her daughters. I recognised Tyburn and Fleet on my left standing with a pair of teenage girls wearing thin braids and cashmere jumpers. Beverley was on my right, looking underdressed in Lycra shorts and a purple sweatshirt. When she was sure I was looking she rolled her eyes. Beside her stood an amazingly tall and slender woman with a fox face, electric-blue and blonde extensions and elongated nails painted in green, gold and black. That, I guessed, was Effra, another underground river, who was clearly moonlighting as the goddess of Brixton market. I noticed that it was north London rivers on the left and south London rivers on the right.

Brent let go of my hand, essayed a curtsey in the direction of Mama Thames and then spoiled the effect by skipping over and hurling herself into her mother’s lap. There was a brief pause in the ceremony as the little girl squirmed her way into a comfortable position.

Mama Thames turned her full gaze on me, and the undertow of her regard drew me closer to her throne. I had to fight a strong urge to throw myself on my knees and bang my forehead on the carpet.

‘Constable Peter,’ said Mama Thames. ‘How nice to see you.’

‘It’s nice to be here. As a token of my respect I’ve brought you a gift,’ I said, hoping that it was going to arrive before I ran out of pleasantries. I heard clinking behind me, and Uncle Bailiff arrived with my crate. He was a heavyset white man with a number two skinhead and a faded tattoo of SS lightning bolts on his neck. He set the crate down before Mama Thames, gave her a respectful nod and, with a pitying look at me, left without a word.

One of the cronies stepped forward to pluck a bottle from the crate and show it to Mama Thames. ‘Star Beer,’ she said. The core product of the Nigerian Breweries PLC, available in the UK from any good stockist, and in bulk if your mum knows someone who knows someone who owes someone a favour.

‘How much has he got out there?’ asked Fleet.

‘A lorryload,’ said Lea.

‘How big a lorry?’ asked Mama Thames without taking her eyes off me.

‘Big lorry,’ said Brent.

‘Is it all Star?’ asked Mama Thames.