I once gave Derek some sturdy advice. If you are going to travel in time, get yourself a really sturdy ledger.
There was a bit more to the advice than that. Get a really sturdy ledger. A big double entry job. And three pencils. Not pens. Pencils never look out of place and ledgers always fit in. You can always erase pencil. That way you can avoid permanent mistakes. Of course, Derek only got half of the idea.
What I told him was to get a really sturdy ledger to record the time he arrived and the time he left and the date and time on his watch. Like double entry book keeping. Recording his own personal time line. Instead, Derek decided a Diary - page per day - would be the best thing. When Derek made mistakes he made big mistakes.
When Derek travelled to 1 March 2018 he used a 2022 Diary. When Derek travelled to 31 July 2003 he used a 2021 Diary. When Derek travelled back to 20 May 1994 he used a 2020 Diary. When Derek travelled to 31 May 1979 he used the 2022 Diary. Which turned out to be a mistake. Possibly.
Sitting in a caravan in North Wales in 2019, Derek had a large, day per date diary open in front of him. Hardback. Blue. With the Central Electricity Generating Board logo on the front. Embossed, in gold lettering: 1979. Threading its way across the space inside the caravan was a seemingly endless skein of wool. On almost every available surface there were pictures, each one connected, via wool, to a page in the Diary.
Derek assured me: this is the best and only way to track down who mugged me.
It seemed obvious, to me, that a vendetta across time was not really the most sensible thing. But, as I said, Derek is mad as a bucket of oily monkeys.
On the floor, with equally byzantine branching wool attachments were diaries for 1976, 1977, 1978, and 1980. All from the Central Electricity Generating Board. When I mentioned this to Derek, he tapped his nose - in the manner of one uttering some deep dark confidence - and announced he had contacts. I asked: and breaker boards. Derek gave me one of those looks. The kind that bode undertakers and weeping relatives. I tapped my nose and nodded.
One of these diaries holds the secret to who mugged me. I have it down to the forty two people who were in the Lesser Free Trade Hall, Manchester, 4 June 1976. I mentioned that Lewis Carroll, in the Hunting of the Snark had used the number 42. And in Alices Adventures there were forty two illustrations. Unlike the breaker board quip, these revelations simply elicited some rapid scribbling and a gratifying nod. Derek then announced that the Answer to the ultimate question, in The Hitchhikers Guide To The Galaxy was also the number 42. After an hour of recreational forty two announcements, Derek slumped and announced that forty two was not going to help. He was mugged by a punk with a mohican.
These Diaries are the secret to where reality bifurcated. So what we need to find is what was the quantum event and what the many worlds are and which is the consensus reality. The consensus reality could be the only one in which he was mugged.
I tried to point out that mugging, even by a time travelling punk with a mohican, was not a quantum event. Derek was not having it.
I changed the subject, citing BMJ 2005;331:1498 -"The case of the disappearing teaspoons: longitudinal cohort study of the displacement of teaspoons in an Australian research institute" - which, as a minor result, reported that the half life of teaspoons in a communal kitchen in a research institute was forty two days. Derek seemed impressed. But wanted to know more about the quantum nature of robbery and time travellers.
How Derek got to be in Wales.
How Derek got tangled up in the first place.
