He led us into the kitchen, a room four times the size of our own, with an old-fashioned flagstone floor, a wide table in the centre and a long range – the grown-up version of our old Rayburn – along one side. The worktop and shelves were arrayed with the latest varieties of kitchen equipment, crockery and utensils.

‘What shall we have? Lemonade, tea, hot chocolate?’ Kit said, opening doors and cupboards randomly, clearly unfamiliar with the kitchen layout. ‘Cook made some biscuits the other day, I think.’

‘Have you got a vase for these roses?’ I asked. ‘They could probably do with a drink.’

‘Of course, of course . . .’ he muttered, pulling open more cupboards. ‘Will this do?’ He brought out an enormous earthenware jug, far too large for the purpose.

‘That’ll be fine, for the moment,’ I said. ‘Where’s the sink?’

‘Oh, it’s out here,’ he said. ‘Let me. This thing weighs a ton.’

At last we were all settled, sitting at the kitchen table with glasses of lemonade and a plate of delicious raisin biscuits.

‘Tell you what,’ Kit said, his face brightening now, ‘how’s about a bit of adventure?’ He turned to Jimmy. ‘You’d enjoy a bit of fun too, wouldn’t you? No climbing walls this time, promise?’

Jimmy nodded, his mouth full of biscuit.

‘Should you?’ I pointed to the bandage. ‘Aren’t you supposed to be taking it easy?’

‘I’m perfectly fine,’ he said. ‘And I’ll go mad if I have to stay indoors a moment longer. Come on, let’s go.’

He led us through the garden, crossing the moat on a narrow footbridge and down a path that led along the bank of the lake for a hundred yards or so, until we reached the wooden structure overhanging the water on stilts that I’d spied from the other side.

‘This,’ he announced, pulling a key from his back pocket, ‘is the boathouse.’

He unlocked the door and pushed it open with some difficulty, inviting us into a dark, dank-smelling space. After my eyes became accustomed to the gloom I realised that the floor of the shed was actually water, with just a narrow walkway all round. Floating, secured with a rope, was a small wooden boat, complete with oars.

‘Let me introduce you to the good ship Mary Jane,’ Kit said. ‘Or, as we sometimes call her, The Jolly Roger. C’mon then,’ he went on, leaping down into the boat.

My brother’s hand crept into mine, and I squeezed it to reassure him.

‘Where are we going?’ I could see no exit to the boathouse, except for the door we’d entered through.

‘Wait and see,’ he said, helping Jimmy down into the boat first, then me. ‘Sit still and don’t stand up unless I tell you.’