‘We need much more,’ Drummond told us. ‘Find out who the killer is and link him to Slack. Prove that it’s Slack or one of his people who is sending out those text messages. Get someone to grass him up. Without some solid evidence we can’t touch the bastard and he knows it.’

Marsden and I pulled together a detailed account of our interview with Eddie Fowler. After feeding it into the system, Drummond told us both to go home and get some rest.

‘I’m quite happy to stay for a couple more hours, guv,’ I said. ‘There’s still a lot to go through in Slack’s file, especially the personal stuff. If I can just find—’

‘That can wait,’ he said. ‘You look knackered, and I’ve told you before that you can’t survive on adrenalin alone. Besides, I want everyone in bright and early tomorrow morning even though it’s Saturday.’

It was four o’clock and already dark outside. I was glad I didn’t have to join the hordes of commuters on the tube. A few security measures had kicked in and one was that wherever possible we had to travel around London in marked police vehicles.

On the way home I phoned Mum and was pleased to hear that she had arrived safely at Sylvia’s house in Ringwood, and they were now sharing a bottle of wine.

‘It’s very festive here,’ she said. ‘Sylvia has already put up her tree and decorations.’

I was reminded that in just under three weeks we were due to fly to Spain to spend Christmas with Aidan’s parents. I honestly didn’t think that would happen now, even if by some miracle this nightmare ended suddenly. I mentioned it to Aidan when I arrived home and he suggested we leave it a week before cancelling the flights.

He started preparing a light meal for us. Cheese on toast with lashings of brown sauce. It was one of my favourites, and as I started digging in I realised I hadn’t eaten all day.

‘I got a call from Balham police station this afternoon,’ he said. ‘They asked if I had any concerns about security and then arranged to give me a lift home from school. It was weird.’

‘But necessary,’ I said. ‘The car that’s parked out front will now be there until there’s no longer a threat.’

‘Well, I have to admit that I do feel safer knowing that it’s there.’

I told him that I was concerned we hadn’t done enough to secure the house.

‘I think we should call a locksmith and get them to fix stronger locks on the front and back doors,’ I said. ‘And we should install some motion-sensor lights as well.’

He agreed and said he would sort it over the weekend as I had to go to work.