There are several decanters, each with a beautifully engraved silver label hanging around its neck. I can see one that says WHISKY, another BRANDY – Garrick’s tipple of choice – and third in the group is SHERRY. It is tempting, but I know Thea would smell it on my breath, so I simply dust the cut glass. There is another decanter, which looks remarkably similar to the sherry one. It has a tag round its neck with just one letter on it: J.

I quickly take the stopper out of the bottle and sniff. Then I do the same with the one labelled SHERRY. They smell identical.

I have the urge to pick up the decanter and hurl it at the window because I suddenly know exactly why it is labelled J. I stand for a full minute, holding it so tightly in my hand that I fear the crystal will shatter. Every woman in the house apart from Thea is known as Judith. I wonder if they have all been dosed with the doctor’s sherry before being moved to the depths of the cellar?

I turn away from the decanters and carry on with my tasks, but my anger mounts as I move on to the other rooms in this part of the house. I need to stick to my schedule because when the clock strikes twelve I am supposed to return my cleaning things to the storeroom and trail back downstairs. The door has been left open for this purpose, and the last one through closes it behind them.

Finally, twelve o’clock comes, and I take my materials back to where they belong. I’m first to pack away because I’m the only one working on this floor, and suddenly I have an idea. I have time to carry out my plan, I’m sure, before the others come downstairs, and Thea and Garrick are nowhere to be seen, so I scurry along the corridor back towards the drawing room. I rush over and smile to myself as I swap the labels on the sherry decanters. Let’s see how Thea feels about being drugged.

I nearly jump out of my skin as the silence of the house is suddenly shattered by the shrill peal of the doorbell. I have never known there to be a visitor, but I do know that Thea will be coming along the corridor from the kitchen, blocking my escape route. The other girls will be on their way down to the cellar now, but I have no way of getting past Thea.

‘Shit!’ I mutter. What if she brings her visitor in here?

I look around, but there isn’t anywhere to hide. I’ll just have to brazen it out and hope that if she invites her visitor into this room, he or she won’t recognise me from the news. With fumbling fingers, I swap the labels back, terrified Thea will give the drugged sherry to someone else.