The only private space in the entire building was the shower in the corner. She went in, locked the door and sat on the bench where she used to change on the days when she ran into the office. Her heart was thumping again, getting faster as fear and anxiety threatened to overwhelm her. She lay down in the basin of the shower cubicle, with her feet up against the bench, trying to slow her breathing. She felt as if she were having a heart attack.

Eventually, the panic subsided, but the feeling of total depletion did not. She curled up in the bottom of the shower tray, like a dog in a basket, and closed her eyes. She could feel the damp beneath her, but didn’t care. All she wanted was some kind of release. It didn’t come, but as she began to plan how she would make it to Russia she could at least begin to focus on something else.

Eventually, Kate stood up. She left the cubicle and ran a basin of cold water. She splashed some on her face and looked at herself in the mirror again. She texted Dr Wiseman’s secretary and asked if there was any possibility of speaking to him – urgently.

She returned to her desk. She took two of the passports with fresh identities, neither of which she had used before, from the drawer and waited until Suzy left the office, then collected a thick wad of dollars, euros and roubles from the safe in the corner. She emailed Julie to say she would meet her at Heathrow in the morning, put on her trainers and started to walk home.

It was a relief to be in the house alone, but that didn’t last long. She had only been home for ten minutes – just enough time for her to be seated at the table with a cup of herbal tea – before her mother called. Kate had an instinct, based on years of experience, that today she shouldn’t answer, that everything would be different. She let the first few calls ring out, but picked up on the fifth. ‘Yes, Mum,’ she said.

‘They’re trying to poison me.’

Kate took a deep breath. A tear crept on to her cheek at the prospect of the familiar downward spiral. ‘Who is?’ she asked quietly.

‘The fat black one.’

‘You mean Lisa?’

‘I don’t know her name!’

‘Because why would you?’ Kate whispered.

‘What was that?’

‘Nothing. I don’t know how many times we’ve been through this, Mum. Or how many more times we’re going to have to. I’ve met every single one of the nurses in the home and they are, without exception, nice and caring individuals. No one is trying to poison you.’

‘Perhaps you put them up to it!’

‘I’m going to end this call now.’

‘Telephone the police! I want to report the black bitch.’