There was an angry growl and a loud whooshing noise as Havisham swept past in little more than a blur; two flashes from the speed camera went off in quick succession and there were several more loud bangs as Havisham rolled off the throttle.

'What was that noise?' asked my mother.

'You'd never believe me if I told you. My – er – husband hasn't been round looking for me, has he?'

'I'm afraid not, sweetheart,' she said in her most understanding voice; she knew about Landen and understood better than most – her own husband, my father, had been eradicated himself seventeen years previously. 'Why don't you come round and talk?' she went on. 'The Eradications Anonymous meeting is at eight this evening; you'll be among friends there.'

'I don't think so, Mum.'

'Are you eating regularly?'

'Yes, Mum.'

'I managed to get DH-82 to do a few tricks.'

DH-82 was her rescue Thylacine. Training a Thylacine, usually unbelievably torpid, to do anything except eat or sleep on command was almost front-page news.

'That's good. Listen, I just called to say I miss you and not to worry about me—'

'I'm going to try another run!' shouted Miss Havisham, who had drawn up. I waved to her and she drove off.

'Are you keeping Pickwick's egg warm?'

I told Mum that this was Pickwick's job, that I would call again when I could, and hung up. I thought of ringing Bowden but decided on the face of it that this was probably not a good idea. Mum's phone was bound to have been tapped and I had given them enough already. I walked back to the road and watched as a small grey dot grew larger and larger until the Special swept past with a strident bellow. The speed camera flashed again and a belch of flame erupted from the exhaust pipe. It took Miss Havisham about a mile to slow down so I sat on a wall and waited patiently for her to return. A small four-seater airship had appeared no more than half a mile away. It seemed to be a SpecOps traffic patrol and I couldn't risk them finding out who I was. I looked urgently towards where Havisham was motoring slowly back to me.

'Come on,' I muttered under my breath, 'put some speed on, for goodness' sake.'

Havisham pulled up and shook her head sadly.

'Mixture's too rich,' she explained. 'Take the film out of the speed camera, will you?'

I pointed out the airship heading our way. It was approaching quite fast – for an airship.

Miss Havisham looked over at it, grunted and jumped down to open the huge bonnet and peer inside. I cut off the padlock, pulled the speed camera down and rewound the film as quickly as I could.

'Halt!' barked the PA system on the airship when it was within a few hundred yards. 'You are both under arrest. Wait by your vehicle.'

'We've got to go,' I said, urgently.