The turnkey steps forward, grips my wrist, yanks me back into place. ‘Sorry,’ I whisper. ‘Sorry.’ I look up meekly, snatch for breath. The judge nods, and he releases me and steps back, but I’ve lost the thread of what the doctor was saying, have to lean forward to pick it up again.

‘. . . it was obvious from the bodice, Mr Pettigrew, just as it was obvious from the body.’ But he blusters when he says it, and looks unsure.

As you take your seat, Jessop gives an annoyed little toss of his head, and I see that, for the first time, there’s a ruffle to his crow-black feathers. He darts a look behind him. ‘I have no further questions for this witness, M’Lud, and, quite frankly, I’m surprised he had to be troubled to come back here for such a damp probing as that.’

But both Jessop and the doctor look up, towards each other, when you say you wish to call Dr John Pears. The courtroom falls silent. All eyes turn to me in the dock, as they do whenever we must stop and wait. Dr Wilkes stops, going up the steps, wipes his hand along his breeches. The room waits. After a few minutes, Tomkin scurries out, comes back in. Shakes his head, then goes out again. You narrow your eyes up at the gallery before turning back to your papers. ‘My Lord, I – ah, might I request a brief adjournment, to take instructions?’

When you come back, you give a twitch of your gown, which hangs flattened and black. It has slipped, and your smile has slipped, too.

‘My Lord, it seems it will be Dr Lushing this morning, not Dr Pears. I wonder if we might adjourn again until the half-hour, to allow him time to arrive.’

‘Very well, Mr Pettigrew. Let’s hope Dr Lushing hasn’t also disappeared,’ says the judge, snickering at his own joke.

Dr Wilkes, arms hooked over the gallery railing, gives a single blunt nod. When I look up again he’s gone, and you are too. Leaving me to wonder what it’s all about.

Doctors all seem to have skittering hands and skin under their eyes that sags like purses. As if it’s a profession that draws men unable to sleep or sit still. Dr Lushing tugs at his side-whiskers while he waits for you to start. You have been shaken by something, I can see it. By what? You draw a deep breath, tap the papers in front of you. You’re composing yourself. You fiddle your gown up, then remind him of my claim to have taken laudanum on the night of the murders, which rendered me unable to remember anything thereafter.

He leans forward. ‘Oh, yes, I was very interested in your client’s claim, Mr Pettigrew. Most interested. It has the hallmarks of a classic stupor. There’s been a great deal of scientific debate recently covering these states. Somnambulism, animal magnetism, mesmerism.’ He ticks them off on his fingers. ‘All of those states seem to involve consciousness and unconsciousness to the same degree and at the same time. A split down the middle, one could say. The person affected can still have the will to act – people have indeed been known to perform very complicated actions – but the moral nature is entirely wanting, because they have lost the regulating power of their own minds. In other words, they are not responsible, not in a moral sense anyway. Somnambulism is more common than the man on the street, or even the man on the jury benches, might think. Alfred the Great was a sufferer, as was La Fontaine. Condillac.