‘Tea?’ said Betsy loudly, interrupting him. She marched back to the kettle, took out another mug, reached for the drawer and hesitated. Starsky retreated to his spot under the table and closed his eyes with a contented snuffle.

I knew exactly what she was thinking: that she couldn’t use her magic alarm with Jensen there because he’d ask too many questions. I decided to come to her rescue just this once. I completely understood why she didn’t want to admit any failings in her health to her beloved grandson; she didn’t want to worry him and five minutes ago I’d have probably sided with her. Now, having smelled her fridge, I couldn’t condone her deception. At this rate it wouldn’t be too long before some sort of disaster occurred and I didn’t want that on my conscience; coming to the Butterworths’ was supposed to signal an incident-free time for me.

‘You open the biscuits,’ I said, handing her the tin, ‘I’ll make Jensen his tea. Or would you prefer coffee?’

‘Coffee please,’ said Jensen, jingling coins in his pockets. After his exuberant entrance his demeanour had changed completely: his smile had been replaced by a weary frown. ‘Gran—’

‘I didn’t hear your car on the drive,’ said Betsy, blatantly ignoring him and wrangling ineffectively with the lid of the tin which I could see was sealed with clear tape but she presumably couldn’t. ‘Such a lovely treat to see you. To what do I owe the pleasure? Oh, this infernal lid!’

Betsy shoved the tin at Jensen who caught my eye with a flicker of amusement.

He picked at the end of the tape, peeled it off with a flourish and prised off the lid.

‘Could have sworn I’d already removed that,’ said Betsy innocently.

I turned away, spooning coffee into Jensen’s mug to hide my smile.

‘My car doesn’t make much noise. Come and look, Gran.’

He beckoned her to the window at the far end of the kitchen which overlooked the yard.

‘What am I looking at?’ she said, pressing her face to the glass.

‘My new car. Just got it last week. What do you think?’

‘Very smart,’ she said, ‘and it’s my favourite sort.’

Jensen laughed. ‘So you know what it is then?’

‘Of course. Silver,’ she retorted, turning from the window, she caught my eye and mouthed, ‘Help!’

I crossed to the window to see for myself. The car was smart: a silver Mercedes, which if I wasn’t mistaken …

‘Is that an electric Mercedes?’ I asked, handing Jensen his coffee.

‘Thanks. Yes, it’s a hybrid.’ Jensen nodded. ‘A new initiative at work to be more eco-friendly. My idea. If we’ve got to be on the road so much, it makes sense to reduce our carbon footprint as much as possible.’

‘What do you do?’ I asked.