‘What the hell was that?’ she said.

‘I beg your pardon?’

‘I led you all to Simone Matthews. I did all the legwork on this case. And if you haven’t forgotten, sir, DCI – sorry, Superintendent Sparks – was taken off the last major murder investigation case for incompetence! I solved this case!’

‘I have no control over decisions made by Oakley.’

‘But you did know a promotion was in the offing, didn’t you? And you’ve kept me at arm’s length. Kept me away, strung me along, made me do all the dirty work!’

Marsh then lost it. ‘Do you know how frustrating it is to see how you operate, Erika?’

‘Don’t call me Erika, we are NOT friends! I am a police officer who—’

‘You were a great officer, Erika, really great, once. But you continue to go against orders, against protocol… Now you’re just…’

‘I’m just what?’

Marsh looked at her for a long moment.

‘You think you have this incredible instinct, but it’s blind luck and stupidity. You’re a vigilante. And you’re on borrowed time. And because of that, you’ll remain DCI Foster. In light of what happened, of you defying orders, refusing to take leave when I ordered you to, I couldn’t recommend you for promotion.’

Erika gave Marsh a long, hard look. ‘Well, I am not sticking around here to take orders from Superintendent Sparks. You’ll have my letter putting in for a transfer first thing tomorrow morning.’

‘Hang on… transfer? Erika!’ said Marsh, but she turned and left the office, walking off down the corridors and out of Lewisham Row station.

Epilogue

It was a warm, sunny day. Erika stepped out of her car. She took off her sunglasses and looked at the small door within a door at the huge Victorian gates of Belmarsh Prison.

She leant on the roof of the car and saw that it was twelve minutes past eleven. He was late.

Moments later, the small door opened with a squeak. Isaac stepped out and looked around him, taking in the clear blue sky, the silence and Erika.

He had a brown paper bag in one hand and his suit jacket over the other arm. He walked towards her, through the gates and out onto the street. They hugged for a long time without saying anything.

‘All charges dropped. I told you so,’ said Erika with a grin.

‘You didn’t tell me so,’ he answered wryly. ‘And why did it take so long?’

‘Forensics. You know what your lot is like. They take ages. Simone Matthews gave them a full confession, but they had to ensure it was her DNA at the Jack Hart murder scene. Moss and Peterson have been keeping me in the loop.’

‘I keep thinking someone is going to come out and tell me it’s a terrible mistake and I’m…’ Isaac put a hand to his face.

‘It’s okay. You’ve been cleared. And you keep your licence to practise medicine.’

Isaac stood for a moment, breathing in the air. Then he opened the car door and got in. Erika went round to the driver’s side and climbed in beside him.

‘What did you mean, Moss and Peterson have been keeping you in the loop?’ asked Isaac. ‘I thought you solved the case?’

‘I did. It’s a long story. The short version is that I’ve put in for a transfer. And I’m taking a break.’

‘A transfer. Where?’

‘I don’t know yet. Marsh is trying to talk me out of it. Hence the break… For the first time in years, I just want to take my foot off the gas. Work out what it’s like to be a normal person,’ said Erika.

‘Let me know when you find out,’ said Isaac, wryly.

They drove away and rode in silence. Isaac put his head back and closed his eyes. A short while later, he noticed they were driving along the high street in Shirley.

‘Why have we come this way?’ he asked.

Erika pulled into a space a little way up from Penny Munro’s house. In the front garden, Penny was standing with a white face, watching little Peter as he held the hose, watering the lawn. He put his thumb on the end of the hose and laughed in delight as the water sprayed back over them both.

‘He’s such a nice kid. Do you think he’ll be okay?’ asked Erika as they watched.

‘Honestly, who knows? You’ve got to have faith that good will win out,’ said Isaac.

‘He’s so young to lose his father, and now the memory of his uncle is forever destroyed.’

Isaac put his hand on hers.

‘You can’t save the world, Erika.’