But then the cast arrived: Tirian, Jordan and Sky, all three of them smartly dressed, smiling and confident, Sky in a pink puffball dress, Tirian wearing what looked like a very expensive black leather bomber jacket. Their appearance brought the party to life. Suddenly the crowd became more relaxed and cheerful. The music rose in volume and everyone had to talk more loudly to make themselves heard. More silver platters of food came out of the kitchen. Even the waiters picked up their pace.

And that was when I saw something so extraordinary that I had to look twice, and even then I didn’t quite believe it and had to look again.

The Sunday Times critic, Harriet Throsby, had come through the front door of the restaurant, accompanied by a younger woman who might have been her assistant or perhaps her daughter. What was going on? Had she decided to go for a Turkish meal after the play and wandered in without realising that this was where the party was taking place? No. As I watched, she helped herself to a glass of wine, sniffing the contents disapprovingly. The younger woman didn’t look happy to be here and Harriet muttered a few words into her ear. Ahmet had seen them both. He went over to them and bowed, gesturing towards the food. They were expected. They had been invited.

But that was impossible, wasn’t it? Critics never attended first-night parties. It was completely inappropriate and might even be seen as unethical. I couldn’t imagine what she was thinking, coming here. Could it be that she was a friend of one of the actors? That was extremely unlikely, given what Ewan had told me, and anyway, it would still have been wrong. Her job was to go home and write whatever she was going to write. She wasn’t part of the production and for all Ahmet’s smiles, she couldn’t be welcome here – particularly if she hadn’t liked the play.

I watched Ahmet leaning towards her, speaking earnestly. It was impossible to hear what he was saying with all the noise. For her part, Harriet was already bored and looking past him. I saw her eyes settle on the man Ahmet had just been talking to – the thin man in the suit. Brushing past Ahmet, she went over to him, smiling as if he was an old friend. The thin man stared at her, appalled. Harriet said something and he replied. Again, the words were lost in the crowd.

As the two of them continued their conversation, I pushed my way through about a dozen people and found Ewan, who was standing next to Tirian Kirke and Sky Palmer. ‘Have you seen?’ I asked.

‘What?’

‘Harriet Throsby!’

Ewan grimaced. ‘Didn’t Ahmet warn you she’d be here?’ he said. ‘She always comes to first-night parties. She expects to be invited … in fact, she insists upon it. Whatever you do, don’t ask her about the play – and I mean the writing, the performances, the scenery … anything. Just don’t go there. She won’t tell you what she thinks. She never does.’