She’s checking for a stroke now, I realise. I force my mouth into a rictus grin. For a moment, I nearly perform the other test activities automatically, before thankfully remembering just in time that delivery drivers probably wouldn’t know what those are. I need to try to get back into character and get out of here as soon as possible.

‘Lift your arms,’ she continues, and I obey, making sure they’re at the same level. ‘Can you remember my name?’

‘Richenda,’ I tell her, ensuring I pronounce every syllable clearly.

‘Excellent.’ She brings out a thermometer and points it at my forehead before pulling on a trigger. ‘Your temperature is also normal,’ she informs me after the machine beeps. ‘I think we can rule out anything serious. So why don’t you tell me what’s really going on?’

‘Vot do you mean?’ I ask her, being careful to use my accent.

‘I couldn’t help noticing the name of the delivery company on the card you started to give me. I had a quick look online when I was getting your drink and it doesn’t seem to exist. Then there’s your accent, which is a little inconsistent, if you don’t mind me saying. And your name. Tilly is a very British name. I did briefly wonder whether you were here to rob me and considered calling the police, but you would never have let me go into the kitchen alone if you meant me harm and you were actually any good at your job. I could have called 999 while I was in there or picked up a large knife to defend myself. Also, you must have known who I was to address the parcel to Luke, which leads me to think you’re connected to him in some way.’

Mentally frail? Bloody hell, this woman would put Hercule Poirot to shame.

‘I have my suspicions,’ she continues, ‘but I’d rather hear the words from you. How do you know my son?’

‘I’m sorry,’ I tell her as I force my legs into action and try to extricate myself from her over-soft sofa. ‘I should never have come. It was a stupid idea.’

‘But you came, stupid idea or not. Why? And why did you expect him to be here?’

She’s clearly not going to let this go. I sink back into the sofa, defeated.

‘He told me he lived here,’ I tell her eventually.

‘Why on earth would he say something like that? I think you’d better tell me everything, don’t you?’