‘It is, Granddad. But you don’t have to do it. Not if you really don’t want to. It’s dangerous, and it’s miles for us to get to the sea . . . and of course, it’s really, really expensive.’

Granddad runs his hand through his hair. ‘Yes, and of course I only have my pension . . . But I’ll think about it. Perhaps I could cancel my subscription for German TV.’

‘No, Granddad,’ I say. ‘Don’t do that. You watch it all the time.’

Suddenly I feel guilty. I walk towards the coffee table for the TV remote.

‘Would you like me to watch Wer wird Millionär with you?’ I ask.

‘No, I don’t want to watch people become millionaires, I am still thinking about scuba diving.’

‘But I said you don’t have to.’

‘I know, but we should find out about it. Look it up on your phone.’

I reluctantly pull my phone out of my pocket. Granddad puts his glasses on and peers over my shoulder.

‘Type in “Bristol scuba diving”,’ Granddad tells me. ‘What does it say?’

‘Umm . . .’ I look at the screen. ‘Umm . . . I think I typed it wrong. It says, “Did you mean: Brickpit Scooba?” ’

‘Oh,’ says Granddad. ‘Try it again. B, R, I—’

‘It’s okay, Granddad,’ I say. ‘I know how to spell it.’ I type ‘Bristol scuba’. But it doesn’t really matter, because once Granddad sees they don’t do scuba diving at the leisure centre and we’ll have to travel miles, there’s no way he’ll—

‘There!’ Granddad points at the screen. ‘Scuba diving.’

‘What? No way!’ I turn the screen towards me. ‘It’s at the docks, Granddad!’ My voice goes high in panic. ‘We can’t go in the docks. It’s full of boats, and fish . . . and crabs!’

‘No . . . No . . . Underneath that one!’ Granddad says excitedly, like when Grandma gave him socks for his birthday. ‘At Speedwell Baths . . . “Bubble Makers – learn to dive and have fun with all the family.” We don’t have to take our family, but it will be good fun with just me and you. I don’t think we’ve done anything like that together since Grandma and I took you Cadbury World.’

‘I don’t know, Granddad,’ I say, wishing my phone would die. ‘It might be dangerous.’

‘Dangerous? No, not in a swimming pool – and they will have qualified instructors, see here. Do that thing with your finger.’

‘Scroll down?’

‘Yes, scroll down.’

I flick my finger up the screen.

‘See, “All lessons are with our master scuba instructor, Mark Slade,” ’ Granddad reads.

‘No, Granddad,’ I say. ‘I really don’t think you should do it.’