'The Eject-O-Hat. I've pulled the records and traced the manufacturing process all the way back to the original milliner; it seems that over a hundred people have been involved in its manufacture, modification and overhaul schedules. Fifteen years is a long service life for an Eject-O-Hat. Add the people with the know-how and we've got a short list of about six hundred.'

'A broad net.'

'I'm afraid so.'

I went to the window and looked out. Two peacocks were strutting across the lawn.

'What was the good news?'

'You know Miss Scarlett at Records?'

'Yes?'

'We're getting married on Tuesday.'

' Congratulations.'

'Thank you. Was there anything else?'

'I don't think so,' I replied, walking to the door. 'Thanks for your help, Plum.'

'My pleasure!' he replied kindly. 'Tell Miss Havisham she should get a new Eject-O-Hat – this one is quite beyond repair.'

'It wasn't Havisham's,' I told him, 'it was mine.'

He raised his eyebrows.

'You're mistaken,' he said after a pause. 'Look.'

He pulled the battered Homburg from his desk and showed me Havisham's name etched on the sweatband with a number, manufacturing details and size.

'But,' I said slowly, 'I was wearing this hat in—'

The awful truth dawned. There must have been a mix-up with the hats. They hadn't been trying to kill me that day – they had been after Miss Havisham!

'Problems?' said Plum.

'Of the worst sort,' I muttered. 'Can I use your footnoterphone?'

I didn't wait for a reply; I picked up the brass horn and asked for Miss Havisham. She wasn't in the Well, nor Great Expectations. I replaced the speaking horn and jumped to the lobby of the Great Library where the general stores were situated; if anyone knew what Havisham was up to, it would be Wemmick.

Mr Wemmick wasn't busy; he was reading a newspaper with his feet on the counter.

'Miss Next!' he said happily, getting up to shake me warmly by the hand. 'What can I do for you?'

'Miss Havisham,' I blurted out, 'do you know where she is?'

W'emmick squirmed inwardly.

'I'm not sure she'd like me to tell—'

'Wemmick!' I cried. 'Someone tried to kill Miss Havisham and they may try again!'

He looked shocked and bit his lip.

'I don't know where she is,' he said slowly, 'but I know what she's doing.'

My heart sank.

'It's another land speed attempt, isn't it?'

He nodded miserably.

'Where?'

'I don't know. She said the Higham wasn't powerful enough. She signed out for the Bluebird, a twin-engined, 2,500-horsepower brute of a car – it almost didn't fit in the storeroom.'

'Do you have any idea where she's going to drive it?'

'None at all.'

'Damn!' I yelled, slamming my hand against the counter. 'Think, Thursday, think!'