Here I am once more, outside Fisher’s ex-housekeeper’s flat, only this time she hasn’t answered the buzzer. It’s almost 9 a.m., so she’s probably at work, although she was home last Friday around this time, so maybe she’s up there but just not answering. I press the buzzer one more time and wait. Still no response. I’m worried Vince will call the police if he doesn’t hear back from Carly soon, and that will open up a whole new can of worms.

I step back down onto the sodden pavement and gaze up at the bay window where I saw Merida Flores the last time I came. Icy rain splashes onto my upturned face, clinging to my eyelashes and running down my neck. I pay it no attention. Her curtains are open today. The room beyond is dark. My guess is that she’s out. I should leave, head back to work and trust that Carly will call me when she’s ready. If Ben’s theory is correct, my devious neighbour could be avoiding me on purpose.

Before I go, just in case Flores is in there and can somehow see me, I stare up at her window with my palms pressed together as though in prayer, pleading. One last attempt to get her attention. To let her see my desperation. My heart jumps a beat as a shadowy figure comes into view. It’s her. She’s there. Our eyes lock for a brief moment. She gives a quick nod and then disappears. Does this mean she’s going to let me in?

I step back up to her front door and ring the buzzer, holding my breath. This time she answers.

‘Tessa Markham,’ she says, like a statement of fact.

‘Hello,’ I say, trying to think of something non-threatening to add, something that will make her more likely to speak to me. ‘I need your help,’ I say. ‘Can we talk? Just for a few minutes?’

The door buzzes, vibrating on its hinges. I give it a push and it swings inwards, revealing a surprisingly bright and welcoming communal hallway, the smell of lemon furniture polish emanating from the woodwork. The place is cleaned to within an inch of its life, not a speck of dirt anywhere.

As I walk up the steep carpeted staircase, one of two doors opens at the top and I spy the diminutive figure of Merida Flores – and that’s saying something given my own vertically challenged state.

‘Hello,’ I say, excited and nervous to finally get to talk to this elusive person who might well hold the key to what’s been going on in my life.

If I were to guess, I’d say Merida Flores is in her early forties. Her dark hair has been pulled back in a severe low ponytail, and she’s wearing black jeans and a dark red sweater. Her hand clutches at a plain gold cross hanging from a chain around her neck.

As I reach the top of the stairs, she steps back into her flat and gestures to me to come in. I take a breath and do as she bids, following her through a small, dim hallway into a living room with a large bay window, beneath which sits a dark wooden table and two chairs. It’s the same window through which we stared at one another moments ago. Like the entranceway, the flat smells of furniture polish.

With the heavy black clouds and the rain streaming down outside, it’s almost dark enough to feel like night in here. Flores clicks on the light switch, but that only makes the atmosphere worse, as strange shadows from the lampshade slide across the room. The two of us stand facing one another, awkward, our arms folded, her slim fingers still fiddling with her pendant.

‘Thank you,’ I finally say, ‘for letting me into your home.’ I find myself speaking slowly, carefully, not too sure how strong her English is. I’m still surprised that she actually allowed me in – I thought there’d be more resistance after all the other times I saw her and she was so keen to get away. But I don’t ask why; I don’t want to give her the opportunity to change her mind.

Flores gives a small nod.

‘My name is Tessa, although you already know that.’

‘My name is Angela,’ she says, her voice low and accented.

‘Angela? I thought your name was Merida. Merida Flores?’

‘Yes, I am Angela Merida Flores. In Spain we have two last names – the mother and the father’s name together, yes?’

‘Oh, okay, I didn’t know that.’

‘Please, sit.’ She gestures to a green fake-leather sofa, which creaks alarmingly as I perch myself on the edge. She takes a seat on the closer of the two dining chairs by the window.

‘I need to ask you some questions,’ I begin.

‘You said you wanted my help.’

Although I’m no longer sure of Carly’s motives, I decide to start off by asking about her disappearance. ‘Yes, my neighbour is missing. She went to see Dr James Fisher yesterday.’

At the mention of his name, Angela pales and begins shaking her head. ‘It’s not good,’ she mutters.

‘Not good?’ I repeat. Carly may not be my favourite person, but now I’m really starting to worry for her safety. ‘Why is it not good? Could Fisher have hurt her? The doctor, Fisher, is he dangerous?’

‘Dr Fisher? Dangerous? No.’

‘So why did you say “not good”?’ I ask. ‘When I mentioned his name just now, you looked scared.’

‘I’m not scared of Dr Fisher. I don’t think he would harm anyone,’ she says.

‘You used to work for him, didn’t you? Are you sure he wouldn’t harm anyone? My neighbour…’ – I can’t bring myself to call Carly a friend – ‘she went to see him and now I can’t get hold of her. She’s not answering her phone.’

‘Dr Fisher is a serious man, but not violent. Not dangerous. He wouldn’t hurt your neighbour, I am sure of it.’

‘Why have you been following me, Angela? I saw you a few times, but you ran off.’

She covers her face with her hands. Is she thinking? Crying? I can’t tell.

‘Are you okay?’ Suddenly something clicks in my brain. I rise to my feet and take a step towards her, a sudden chill sweeping my body. ‘Harry said an angel brought him to me. Your name is Angela. Was it you? Did you bring Harry to my house?’

She takes her hands from her face and stares down at her knees, her expression one of dark turmoil. ‘Harry’s mother, she used to call me her angel. God rest her soul.’ She makes the sign of the cross. ‘Harry would copy her and call me his angel, too. It was a sweet joke.’

‘So it was you!’

‘Mrs Fisher was a wonderful woman,’ Angela continues. ‘I was so sad when she died. It was such a terrible thing for the boy to lose his mother like that.’

‘But why did you bring him to my house?’ I ask, staring down at her. ‘It was you, wasn’t it?’

‘You’re right. It was me who brought Harry to your house.’

I’m astounded by her admission and utterly confused. ‘Why? Why would you do that? And you’ve been following me since then, maybe even before this all happened. It’s something to do with Dr Fisher, isn’t it?’

Angela finally looks up at me. ‘Tessa, I’m sorry. I didn’t know that the newspapers would say all those things about you. I didn’t know that bringing Harry to you would cause so much trouble. But she wanted me to do it. I promised her I would do it.’

‘Who? Who did you promise? Is this something to do with Carly? Did she offer you money?’

Angela’s hand flies back to the cross around her neck. ‘All right, please sit back down, and I will tell you.’

So I do as she asks and sit back on the creaky sofa, my heart thumping wildly, wondering just what it is this woman is about to reveal.