Widdy (as I called him) was an enormous, black Tom (no relation) who pretty much walked into my workshop (and life), when it was in the middle of town, and I don't know where he came from. He was obviously hungry and uncared for, so I started to feed him up. He was a gentle little giant - I have never known a cat with a better temperament.
I cut a hole in the wooden door and taught him how to go through it a couple of times, and made him a bed under a table, but I began to notice that he didn't use it at night, preferring a nearby timber-loft up a steep ladder. For the first few weeks, I hardly got any work done because he would lie on my lap and sleep in security, purring occasionally and catching up on the forty winks that he obviously didn't get at night. Then one day, I found out why.
I came to my workshop with H.I. one morning, and after I had unlocked the door and gone in, I saw Widdy staring at me from under the workshop table, looking nervous and frightened. Then I realised - it was not Widdy. It looked exactly like him - same size, same eyes, same small tuft of white fur on the chest - but it was not Widdy.
H.I. said 'of course it was him', but I knew it wasn't. Then - confirming my belief - the Widdy look-alike rushed past me and bolted through the door, colliding with H.I.'s legs on the way out. That convinced her.
Widdy had a twin brother who obviously made his life hell at night, and it was he who sprayed the inside of my workshop with a foul smell. I eternally regret blaming Widdy for that, poor little sod.
One day, Widdy arrived late in the morning, horribly scratched up and injured, so I brought in a vet and gave him anti-biotics. A few days later he disappeared all together and I never found out what happened to him, despite spending weeks searching for him everywhere, including by boat up the river, rowing along for about a mile in both directions and calling out his name.
For weeks afterwards, people would telephone me to say that they had seen him somewhere in town, and I would go there to find a black cat which was not him. I never did find out what happened.
Strangely, when Widdy disappeared, so did his twin brother. I never saw either of them again.