‘The letters were signed by “Mary” and the note by “M”. So who is Mary?’

Joanne’s expression turned from confusion to fear in a matter of seconds.

‘I don’t know anybody called Mary.’ Her voice wobbled as she spoke and she clutched her cardigan tightly around herself.

My God – was Mary a pseudonym? Nell glanced to Paul and could see he saw it too. She decided to go in hard.

‘Ms Fowler, why are you sending letters to bereaved parents and using a pseudonym to do so? Isn’t that a bit insensitive, in light of your own bereavement?’

Joanne looked as though she could launch across the table and grab Nell by the throat, which was exactly the reaction she’d wanted.

‘The fact I know how it feels to have a baby die is exactly the reason I wouldn’t write such a note. I am not here to bring additional pain to another mother.’

‘What are you here for then? To get revenge on Ms Graham?’

‘I’m here because you dragged me in here. I can assure you I’ve seen a lifetime’s worth of interview rooms, and I don’t welcome the fact I’m now back in one because of your stupid assumption I’m someone called Mary.’

‘Are you Mary?’

Joanne looked confused. ‘What?’

‘You said I think you are Mary. But I merely said I thought you were using the name Mary to distance yourself from the threats made against Ms Graham. The two are very different.’

Joanne contemplated her for a moment before replying. ‘My name is, and has always been, Joanne.’

‘And your surname before you were married?’

‘Rathbone.’

‘And where did you grow up?’

‘Portsmouth.’

Nell nodded. ‘Nice. By the sea.’

Joanne shrugged. ‘It was OK.’

‘Were you close to your parents?’

‘What has this got to do with anything?’

‘Just answer the question, please.’

‘Not really. I was adopted because they thought they couldn’t have kids, but when they had two of their own they forgot about me.’

It was a frank admission and took Nell by surprise.

‘I’m sorry about that.’

‘I doubt you are, Sergeant.’

‘Can you tell me your parents’ names and those of your siblings?’

‘None of them are called Mary, if that’s what you’re looking for.’

Nell smiled. ‘Just the names please,’ then noted them as Joanne spoke.

‘Thank you. Do you happen to know what name you were given at birth?’

Joanne stared at her, horrified, and even Paul shifted a little uncomfortably in his seat.

‘Well?’

‘I haven’t seen my birth certificate.’

Nell doubted that was true. ‘What about your husband?’

‘What about him?’

‘Does he share your obsession with Ms Graham?’

‘He blames her as much as I do, if not more, if that’s what you mean.’

‘He was very supportive of you during that time. Must have been hard on him.’