The Tate Modern is dominated by the turbine hall, a vast cathedral-like space that is high and wide enough for even the largest artistic ego. I’d come with the school once to see Anish Kapoor’s dirigible-sized pitcher plant thing that had filled the hall from one end to the other. Ryan Carroll didn’t rate the whole hall, but he did have the elevated floor that projected across the middle.

Because of the crowd I had to get quite close to the sculptures before I could see them properly. They were made out of shop mannequins with what looked like bits of steam-powered technology riveted into their bodies. They’d been posed as if twisting in agony and their facial features ground down until they presented smooth faces to the world. It reminded me uncomfortably of Lesley’s mask or the head of the Faceless Man. Brass plaques were attached to the mannequins’ chests, each etched with a single word: Industry on one, Progress on another.

Steampunk for posh people, I thought. Although the posh people didn’t seem particularly interested. I looked around for another glass of fizzy wine and realised someone was watching me. He was a young Chinese guy with a mop of unruly black hair, a beard that looked like a goatee that had got seriously out of hand, black square-framed glasses and a good-quality cream-coloured suit cut baggy and deliberately rumpled. Once he saw he had my attention he slouched over and introduced himself.

‘My name is Robert Su.’ He spoke English with a Canadian accent. ‘I’d like, if I may, to introduce you to my employer.’ He gestured to an elderly Chinese woman in what was either a very expensive dove-grey Alex and Grace suit or the kind of counterfeit that is so well done that the difference becomes entirely metaphysical.

‘Peter Grant,’ I said and shook his hand.

He led me over to the woman who despite her white hair and a stooped posture had a smooth unwrinkled face and startlingly green eyes.

‘May I introduce my employer Madame Teng,’ said Robert.

I gave a clumsy half bow and, because that didn’t make me look stupid enough, I clicked my heels for good measure. ‘Pleased to meet you.’ I said.

She nodded, gave me an amused smile and said something in Chinese to Robert, who looked taken aback but translated anyway.

‘My employer asks what your profession might be,’ he said.

‘I’m a police officer,’ I said and Robert translated.

Madame Teng gave me a sceptical look and spoke again.

‘My employer is curious to know who your master is,’ said Robert. ‘Your true master.’

With the emphasis he put on the word master I was certain he was talking about magical rather than administrative.