We headed north-west up Mea She’arim Street amid a stream of traditionally dressed Orthodox, past barred shopfronts and badly parked delivery trucks. The apartment buildings above were shabby, unloved. Everywhere walls fluttered with fly-posters printed in Hebrew, roofs bristled with scaffolding. Most of the buildings were either being renovated or looked like they ought to be. Wrought iron balconies peeling ancient paint overhung the street; many were sealed off with plastic sheeting from the rooms inside. It was a couple of degrees cooler than the coast, and bright white candyfloss clouds piled up on the horizon. I was glad of the jacket Baaz had bought me in France.

I was glad, too, that the road signs were in English and Arabic as well as in Hebrew. Even though I’d memorized our route from a satellite image of the quarter that Baaz and I had recced that morning using a VPN on his laptop, the visual check of the street names was reassuring. We turned left on to HaRav Shmuel Salant Street and then, at a huge and what looked like newly built synagogue on the corner, wheeled off north again up an alley that disgorged us both at the sharp elbow of a junction thirty metres off the main drag. We kept walking. I kept my head down and told Baaz to do the same. A hundred metres or so further on I swung us left down Hevrat Mishnayot.

It was an unkempt backstreet, lined with parked cars and graffiti-stained walls, and a dozen or so metal doors leading into buildings and passageways. Dead ahead a huge stone building loomed up – two massive storeys high and fifteen metres wide, with stone arches supporting a tier of impressive, ornate windows. It dwarfed the low-rise stone and stucco boxes that opened up into a sort of plaza in front of it. On either side the road divided. Baaz and I looked around, perplexed. If this was Ezra’s idea of a joke, I struggled to see the funny side.

‘And he didn’t say anything else?’ Baaz shook his head. ‘Sure? I mean, really sure?’

The whole ‘traitor’s gate’ revelation had come completely out of the blue. I shuddered to think what else Baaz had forgotten to mention. He rolled his eyes at me as if I was being unreasonable by asking again.

‘Sure.’

I lit a cigarette and looked around.

The main entrance to the large building was framed by an archway three times my height. Above it, the only sign indicating what the purpose of the building might be had been obliterated with black spray paint. It looked like a synagogue, maybe, or a religious school – though it could just as easily have been an apartment block. Two young men in smart black hats chatted on the corner opposite. Long skeins of white wool dangled from their shirts, hanging down their thighs. Laundry strung out on the balconies above rippled in the breeze.