Gilbert moved out this weekend and I shall miss him quite considerably.

It's true that he was plain to the point of being ugly, but what he lacked in looks he more than made up for with a steady, determined, no-nonsense personality.

He was the strong, silent type - I don't think I heard him utter more than three sounds in the fortnight he was with me. He was also sober, ate all his greens, never looked at another woman and, a big bonus, never ever came in the house.

It was The Mother who introduced me to Gilbert. Friends had asked her to feed and keep an eye on him while they were on holiday.

"Come and have a look," she said, stuffing a lettuce in her carrier bag.

"Why?" I asked. "Seen one tortoise and you've seen them all."

But I went with her and yes, as I said, seen one tortoise and...

I should have known that The Mother had a plan. Gilbert, she said, was obviously lonely and missing his owners.

I told her I very much doubted that and asked her to supply evidence to support this theory.

She didn't, of course, but told me instead she was worried about the responsibility of caring for such a valuable beast. Tortoise rustlers, she said, would have him if they knew he was alone and unprotected.

I don't know why I bought the story - peace and quiet I suppose - but that's how Gilbert came to move into my garden.

"Why not your garden?" I asked The Mother.

"Impossible with the dog," she replied. "You know how territorial she is. She'd get very upset if she saw another animal, an intruder, on her patch."

Yes, I thought, they'd probably fight to the death.

So Gilbert was transported to my house in a cardboard box, looking like a large, hard-baked pie surrounded by straw.

He did not seem over-impressed with his new surroundings, but then it's difficult to detect strong emotion on a tortoise's face.

"What he really likes," said The Mother, "is a crust of bread covered in Marmite."

"Lightly buttered?" I asked. She didn't reply but someone snorted. I think it was Gilbert.

I suppose it says quite a lot about my life and relationships when I tell you how fond I became of that tortoise. Every morning I would go out into the back garden to find where Gilbert had hidden himself and personally serve him breakfast.

Then Gilbert went missing - one morning he simply vanished. How do you try to attract a tortoise's attention? Do you shout its name? Do you whistle?

Obviously not, at least as far as Gilbert was concerned. He had apparently done a runner, which is quite a feat for a tortoise living in a walled garden with no gate.

Had he tunnelled his way to freedom? Taken up rock climbing? Been snatched from his sanctuary by a bird of prey?

It was the dog that saved the day - and Gilbert's crusty life. Her interest in a bin liner filled with garden waste revealed Gilbert happily ensconced among the grass cuttings and dandelion heads.

The Mother returned him to his own plot the following day.

What, she said, could we possibly have told Gilbert's owners had he really gone missing?

"Tortoise rustlers," I replied.

"Of course," she said.