The young, handsome one smiles so warmly I find it difficult to believe he knows how to use the assault rifle that he is holding across his body with the casual relaxedness of an athlete carrying a tennis racket. ‘Do you have a reason for being here?’

‘Yes. To see somebody.’

He nods, as if this explains everything. ‘You see, they know when you’re coming. If they expect you, the door opens.’ He and I both stare hopefully at the wood. Nothing happens. ‘It’s not looking good, is it?’

‘I suppose it isn’t.’

‘Do you have an appointment?’

I shake my head, slightly, as if the diminished quality of the gesture will make it less true.

His partner, who I am already thinking of as Bad Cop because of his glower, rakes a hand across his salt-and-pepper head. The hair is so short I think he must use a mini-strimmer around his cap of baldness. ‘Would you like to move on to elsewhere?’ Bad Cop says.

No I would not fucking like to move on to elsewhere. ‘If I can just explain to someone inside . . .’

‘I appreciate that, but you need to move away from the door.’ Bad Cop points to the other side of the road.

Good Cop is looking at me with sad concern, the kind of eye-narrowing, head-nodding understanding people show each other at funerals. If he weren’t holding a gun he’d be thoughtfully resting his chin on his hand as he nodded.

‘You are committing a criminal offence,’ Bad Cop says.

I turn to Good Cop, as if he is my only means of rescue. ‘How is that even possible?’

‘This has been designated a protective site under the Serious Organised Crime and Police Act.’ Good Cop must practise his gentle solemnity in front of a looking glass.

‘The criminal offence,’ says Bad Cop, ‘is that you crossed the outer boundary without permission. The boundary includes the pavement you’re standing on.’

I never really thought Martin would simply invite me in and then confess all of his official secrets, though I can’t pretend I haven’t had that fantasy. But my real reason for coming here is more modest than that. To get his attention, to leave a kind of calling card so he knows I am done with being quiet and invisible, and to press them to rethink what they are willing to share with me. It is the same message I gave Maxine earlier today. And George before that. These are not people who welcome noise. And I am no longer a person who can refrain from making it.

‘The man I need to see goes by the name of Martin,’ I say.

‘And you are?’ says Bad Cop.