She cursed, moving through to the living room where she saw the digital clock on the oven was dark. She opened the tiny cupboard housing the electricity box, yanked out Marcie’s blotchy painting and flicked the mains switch on and off, but nothing. Peering out of the front bay window at the empty street below, she had no clue what the time was. She opened her front door, crossed the landing to the door opposite and knocked. A few seconds later she heard a key turning, bolts shooting back and the rattle of a chain. The door opened a few inches and a small elderly lady with a meringue of white hair peered through the gap.

‘Sorry to bother you,’ said Erika. ‘Could you tell me what the time is?’

‘Who are you? Why do you want to know the time?’ the lady asked suspiciously.

‘I’m your new neighbour. I think we’ve had a power cut, and my only clock is on my phone, which is also dead.’

The old lady pulled back the thin sleeve of her cardigan and peered at a tiny gold watch biting into the flesh of her wrist. ‘It’s ten and twenty past,’ she said.

‘Ten twenty in the morning?’

‘Yes.’

‘You’re sure?’ said Erika in horror.

‘Yes dear, I’m the one with the watch. My electricity seems to be working,’ she said, flicking her hall light on and off. ‘I think you need to feed your meter, dear. The tenants before you got very behind on their bills. The police even came in at one point – I don’t know why the police were wasting their time chasing up unpaid bills. Although your landlord is apparently quite a high-up policeman, so I’d be careful . . .’

Erika arrived breathlessly at Lewisham Row Station at quarter to eleven. Woolf was on the front desk. He crossed round to her side.

‘DCI Foster, I’ve been asked to take you in to see Chief Superintendent Marsh; it’s urgent.’

‘I know where it is,’ snapped Erika. She went through to Marsh’s office and knocked. Marsh opened the door.

‘Come in and sit down,’ he said coldly. Assistant Commissioner Oakley sat in Marsh’s chair. Marsh had been relegated to a chair beside his own desk. His office had been hastily tidied. The corner of a Christmas card poked out from one of the cupboard doors.

‘Good morning, DCI Foster. Please have a seat,’ said Oakley, in calm, clipped tones. He was immaculately dressed: his uniform crisp, his grey hair neatly parted, not a hair out of place. His skin was tanned and shiny. He was like a sleek fox. Not in any way sexual, but cunning and immaculately groomed. Erika remembered she’d read that if foxes are fed on the finest food they have the glossiest coats. Erika sat and noticed that Marsh was pulling on a pair of latex gloves.

‘Please can we see your mobile telephone?’ said Oakley.

‘Why?’

‘You are the last person to have received a phone call from the murder victim Ivy Norris. The voicemail and your phone is now evidence in the investigation.’ His tone was final; no questions were to be asked. Erika took out the phone and handed it to Marsh.

‘It’s not switching on,’ said Marsh, turning the phone over and pressing the power button.

‘The battery’s dead,’ said Erika.

‘This is your designated phone, for work purposes, and it’s dead?’ asked Oakley.

‘I can explain . . .’

‘Please read out the serial number,’ said Oakley, ignoring Erika. Marsh worked quickly, pulling the back off the phone and reading the number out as Oakley wrote it down.

‘It’s possible to access my voicemail independently, without needing the handset,’ said Erika, as Marsh placed her phone into a fresh plastic evidence bag, and sealed it up.

Oakley ignored her and opened a file. ‘DCI Foster, do you know why you are here?’

‘I think so, sir. I’m not sure why you are though?’

‘Three days ago, an official report was filed by Desk Sergeant Woolf. It details an incident between yourself and Ivy Norris’s seven-year-old grandson, Matthew Paulson. Ivy Norris, whose body was discovered last night.’

‘I’m aware of that, sir. I was one of the first responders at the scene,’ said Erika.

‘It says in Woolf’s report that during the incident in the reception area of this station you physically struck the boy on the back of his head. What do you have to say about that?’ The Assistant Commissioner looked up at her from the file.

‘Is it also mentioned in the report that at the time, the boy had latched onto my hand with his teeth?’ said Erika.

‘What were you doing in such close proximity to the child?’