Cold seeped through the thin soles of Lou’s slippers. ‘I don’t know what to say … I’m … I …’

‘Take a breath, Louisa. Calm yourself. You can ask me anything, and I will try my best to answer you truthfully.’

Was she really about to say what she was about to say … ‘But how? I don’t understand how this can be happening.’

‘That’s because you are looking for a logical explanation when there is none to be found. You must look more to the … spiritual.’ Mrs Hart laughed softly. ‘You can imagine how ridiculous I feel saying that. My whole life has been driven by reality and logic, yet here I am, advising you to find an intangible answer in the ether. But there we are. It’s only fair that I talk plainly so you understand your position.’

‘Understand? I’m not sure that I do. I’m not sure of anything.’

‘Well, there is one thing you can be sure of. And it’s that this dear little chap is looking after you. Bertie is your connection with this house. I lost that ability – if that’s what you would call it – when Elizabeth left. I’m rather glad. I couldn’t have borne to see anybody else leave so abruptly. But now, you are here, our first special guest since Elizabeth, and that is to be celebrated.’

‘But I’m not the first. There was another girl. She left the day I arrived. Bertie told me –’

‘Don’t continue, Louisa!’ Mrs Hart interrupted suddenly. ‘I can’t know where you came from or anything about you. It’s part of the rules, if you like. When Bertie talks to you, he’s asleep. He has no awareness of what has passed between you. He will sometimes recall the residue of what has been said, as though it were a dream, but you mustn’t let him know you are aware. I’m only talking candidly so that you understand your situation. I don’t pretend to know the rules. I can only act on what I sense.’

‘But if it’s one in, one out, how can we both have been here at the same –’

‘Louisa, please!’ Mrs Hart snapped. She paused and looked down at Bertie’s face. Her voice regained its normal measured tone when she continued. ‘I had no idea that anything unusual occurred between Elizabeth and I, until she confided that, while asleep, I sometimes spoke to her about something called “one in, one out” and told her that she had come to stay because we needed her and she needed us. It was then that she confided that we weren’t actually related.

‘From that day, I sensed that we shouldn’t be speaking about how or why she had come to be at Hill House, so we only ever talked in whispers and away from the house. She told me that her family had all been killed in a war. She said that terrible flying machines had dropped bombs from the sky killing thousands and thousands of people. I didn’t believe it. I thought it must have been in a dream that these fantastical notions came to her and she only felt as though they were real memories. It was less than a month later that she left and never returned. To this day, I don’t know if it was because we talked about her past that she was taken from me. I would rather believe that it was because it was her time to go. That she had found what she needed from Hill House, and it was time for her to return to her own life. I just wish that I’d had the chance to say goodbye.’