‘Hmm.’ Plainly unconvinced. ‘Daphne only thinks she’s a secret agent. It’s an old joke from when we were children. We grew up during the Cold War. The pigeons are just a game, but also a practicality for me. You know how I feel about digital communication – I like to have analogue options for important things in case of emergency. I’d use smoke signals if I could.’

‘But she told me she’d been given a mission, a target. Wait . . . are you the one sending her the messages? Are you the Agency?’

O stares at me with those cunning blue eyes. ‘She gets carried away. She was always jealous of my role in MI5 when she was stuck being a housewife. She would have made an excellent field agent, but I’m more of a behind-the-scenes person.’

‘But it’s not just a fantasy, O.’ I catch myself raising my voice and lower my tone to a whisper, leaning towards her. ‘I saw your sister open up Bernard’s back with a key. I saw her climb inside and manipulate him into the situation that got him killed. It was fully calculated.’

She moves her chair away from me a little, avoiding eye contact.

At last, she says, ‘It is terribly regrettable, that Bernard died. Worse, that you had to see it. But how can you be sure it was Daphne and not your subconscious manifesting as Daphne?’

‘Because my subconscious can’t make people sleepwalk! Because she said she’d been given a target and she acted. Are you really going to deny what I’m saying? How can I make you see . . . ?’

My voice peters out. She doesn’t believe me. She’s shaking her head.

‘The whole thing is a mess. It’s going to cause a lot of trouble for Little Bird if BigSky get wind of what happened. They’ll try to use Bernard’s death to grab the IP for your study, and who knows what they’ll do with it once they have control.’

My teeth are chattering. I still remember the way the Creeper loomed over me, how hard it was to breathe, impossible to move . . . How can she be so dispassionate? A man is dead. Two people are dead, but I don’t dare mention Mel or I’ll make myself pass out with fear. I’m amazed I’ve been able to stay awake long enough to have this conversation. Normally my narcolepsy would have felled me a few sentences in.

‘Can you do it, is the question,’ O says, still watching me keenly. ‘Can you disable R.E.M. atonia? Can you trick someone into sleepwalking?’

‘No! Of course not! I never tried—’