I’m not sure what I was expecting as we step inside: something a bit gloomy with tools and stuff all over the place, like the pictures in storybooks when I was growing up, I suppose. This is nothing like that. It’s a bright and airy space, with clear workbenches and tools hanging neatly on the walls. There’s a large drill in one corner, a power saw of some description and another machine I don’t recognise taking up a considerable amount of space by the far wall.

‘That’s his lathe,’ Will explains, evidently clocking my look of puzzlement. ‘Pride and joy. Well, apart from the helicopter, of course.’

‘I’m sorry. Did you say helicopter?’

Will points to an enormous object covered with a blanket. ‘Most of what you see in here is dedicated to the maintenance of that,’ he tells me.

‘When you said your dad was into model aircraft, I kind of had something a bit smaller in mind. That’s huge!’

‘And I’m not going to dare to move the blanket to show it to you, because he’ll know. The good thing is that he’s had a clean-up in here, which means he’s starting to re-engage. If anything is going to help him, it’s this. You know how some women describe themselves as golf widows? Mum used to say she was a helicopter widow in the flying season, because he’d be out every weekend with it when the weather was good enough.’

‘Hang on. Are you telling me that the monster under that blanket actually flies?’

‘Oh, yes. It’s remote-controlled. He belongs to a club and they get together to fly whenever they can, hence Mum’s “widow” complaints. She wasn’t, of course, because she’d always pack a thermos and some sandwiches and go with him. But, when she got too ill to do that, he stopped going and it all got a bit sad in here. He’d come out here sometimes, but I’d watch him from the house and he’d just be sitting at the bench, staring into space. The fact that he’s tidied up is a good sign, I reckon. Having said that, it means that he’ll definitely spot if anything’s out of place so we’d better go before one of us accidentally disturbs something and risks detection.’

Once again he takes my hand to lead me back down the path to the house, only releasing it once I’m safely indoors.

‘Will,’ I ask. ‘Tell me it’s none of my business if you like, but how long can you stay with him, realistically? He’s very reliant on you at the moment, and I worry he’ll nosedive again when you leave.’