Two more shots . . . and then it was like being mugged by an old fashioned gentleman’s club – a wave of brandy, cigar smoke and pheasant that had hung too long. Then, mixed in with nutmeg and the shine of silver, the heated excitement of the mob, the creak of wood under strain and the smell of old rope, defiance and fear.

And rising above it like a clear note in a trumpet solo, the smell of wood smoke and fresh caught fish cooked over an open fire.

Then silence.

‘What was that?’ asked Stephanopoulos.

‘Okay,’ I said. ‘We need to get in there now.’

‘And the Americans?’ she said.

‘Yeah, we need to go save them from a fate worse than enforced river conservation,’ I said. And then, quickly, ‘We have to rescue them from Tyburn.’

Everyone stared at me – strangely they weren’t keen. I could tell.

‘I’ll go in first, check they’re okay and then you guys can secure this level and I can finally get to the garage,’ I said and Stephanopoulos nodded. Guleed came with me because it’s always good to have a witness when things get complicated – especially one that senior officers trust.

The magical duel was still going on upstairs, I could feel it, but the crashes and bangs had abated. It was probably getting subtle – which was all the more reason for me to stick to the plan.

Me and Guleed eased through the door and out into a long corridor that ran the length of the complex. It had a lush grey carpet, cream walls and the same hushed claustrophobia as a modern hotel. There was a haze in the air and I thought I smelled gun smoke.

There was tinny music coming from our left so we went that way, past a pair of lifts and another staircase, through a fire door that had been jammed open with a fire extinguisher. There was another corridor beyond and half-way down its length a pair of open double doors. I smelt chlorine as we crept along the wall and the music, from somebody’s phone speaker I guessed, changed track – a mid-’70s band murdering a pair of guitars and a saxophone. Beside the open doors somebody had helpfully left a Waitrose bag full of Glock 17s. I kept watch while Guleed checked them out.

‘Three,’ she said which, plus the one in the stairwell, should account for all the Americans. Assuming they didn’t have back-up pieces strapped to their ankles.

We slipped inside ever so quietly, into the atrium of what I guessed was the famed underground swimming pool. The music was coming from straight ahead and over it we heard water splashing, shouts and the unmistakable sound of somebody smacking a ball around.

Guleed gave me a questioning look, but how the fuck was I supposed to know what the sounds meant?