I opened a door that led into a small kitchenette. Attached to the fridge was the précis of Caversham Heights. I flicked through it. The sequence of events was pretty much as I remembered from my first reading in the Well, although it seemed that Mary had overstated her role in some of the puzzle-solving areas. I put the précis down, found a bowl and filled it with water for Pickwick, took her egg from my bag and laid it on the sofa, where she quickly set about turning it over and tapping it gently with her beak. I went forward and discovered a bedroom where the nose turret would have been, and climbed a narrow aluminium ladder to the flight deck directly above. This was the best view in the house, the large greenhouse-like perspex windows affording a good view of the lake. The massive control wheels were set in front of two comfortable chairs, and facing them and ahead of a tangled mass of engine control levers was a complex panel of broken and faded instruments. To my right I could see the one remaining engine looking forlorn, the propeller blades streaked with bird droppings.

Behind the pilots' seats, where the flight engineer would have sat, there was a desk with reading lamp, footnoterphone and typewriter. On the bookshelf were mainly magazines of a police nature and lots of forensic textbooks. I walked through a narrow doorway and found a pleasant bedroom. The headroom was not over-generous but it was cosy and dry and was panelled in pine with a porthole above the double bed. Behind the bedroom was a storeroom, a hot-water boiler, stacks of wood and a spiral staircase. I was just about to go downstairs when I heard someone speak from the living room below.

'What do you think that is?'

The voice had an empty ring to it and was neuter in its inflection – I couldn't tell whether it was male or female.

I stopped and instinctively pulled my automatic from my shoulder holster. Mary lived alone – or so it had said in the book. As I moved slowly downstairs I heard another voice answer the first:

'I think it's a bird of some sort.'

The second voice was no more distinctive than the first; indeed, if the second voice had not been answering the first, I might have thought they belonged to the same person.

As I descended the staircase I saw two figures standing in the middle of the room staring at Pickwick, who stared back, courageously protecting her egg from behind the sofa.

'Hey!' I said, pointing my gun in their direction. 'Hold it right there!'

The two figures looked up and stared at me without expression from features that were as insipid and muted as their voices. Because of their equal blandness it was impossible to tell them apart. Their arms hung limply by their sides, exhibiting no body language. They might have been angry, or curious, or worried, or elated – but I couldn't tell.