‘Thank you very much – I will,’ I said, proving once again that a little sarcasm is a dangerous thing.

‘What?’ Mellissa took a step backwards and stared at me. ‘I was joking.’

But I wasn’t. The first rule of policing is that you never take anyone’s word for anything – you always check for yourself. Missing children have been found hiding under beds or in garden sheds on properties where the parents have sworn they’ve searched everywhere and why are you wasting time when you should be out there looking? For god’s sake it’s a disgrace the way ordinary decent people are treated as criminals, we’re the victims here and, no, there’s nothing in there. Just the freezer, there’s no point looking in there, why would they be in the freezer, you have no right . . . oh god look I’m sorry, she just slipped, I didn’t mean to hurt her, she just slipped and I panicked.

‘Always best to be thorough,’ I said.

‘I’m fairly certain you’re violating our human rights here,’ she said.

‘No,’ I said with the absolute certainty of a man who’d taken a moment to look up the relevant legislation before leaving home. ‘Your granddad took an oath and signed a contract that allows accredited individuals, i.e. me, access on demand.’

‘But I thought he was retired?’

‘Not from this contract,’ I said. It had actually said until death release you from this oath. The Folly – putting the old-fashioned back into good policing.

‘Why don’t you show me round?’ I said. And then I’ll know you’re not off somewhere stuffing body parts into the wood-chipper.

Number one Moomin House may have looked like a Victorian folly, but was in fact that rarest of all architectural beasts – a modern building in the classical style. Designed by the famous Raymond Erith, who didn’t so much invoke the spirit of the enlightenment as nick its floor plans. Apparently he’d built it in 1968 as a favour to Hugh Oswald who was a family friend, and it was beautiful and sad at the same time.

We started with the two little wings, one of which had been extended to house an additional bedroom and a properly-sized kitchen. As an architect Erith might have been a progressive classicist, but he shared with his contemporaries the same failure to understand that you need to be able to open the oven door without having to leave the kitchen first. An additional bedroom had been added, the no-nonsense brass bedstead augmented with a handrail, the floor covered in a thick soft carpet and any sharp corners on the antique oak dresser and wardrobe fitted with rounded plastic guards. It smelt of clean linen, potpourri and Dettol.