I was sitting quite still at the typewriter when a plump mouse emerged from under the fridge and crossed the kitchen floor, moving by monorail. Conscious suddenly of another presence, the mouse paused and cast a speculative and I thought conciliatory eye over me. His fur was a rich chocolate, his eye beady with interest.

Catriona — thank God! — was in the room above reading the paper. I heard her laugh out loud. ‘This woman!’ she called down. ‘She’s totally amazing!’ ‘Oh yes?’ I said. ‘In what way amazing?’ ‘She’s had all her toes cut off,’ she said. ‘She’s a cousin of the Queen.’

I looked at the mouse and shrugged. A French country mouse is a pretty, guileless thing. Very quietly, in case Catriona heard me, I sang to it, ‘For he’s a jolly good fellow’, because this apparition of pure nature, quiet and unexpected, felt like an honor. Fixing his shiny black eyeball on me, the mouse weighed the matter up. Finally he concluded that on the whole he would be safer back underneath the fridge and returned there on his monorail.

Catriona greets babies and animals on their own terms. But not the mouse. If she sees a mouse, Catriona spills her popcorn. Restoration of equilibrium can take days. So for all of our sakes — mine, Catriona’s and the mouse’s — I kept quiet about it. But three mornings later, the bloody idiot ran out from under the fridge when Catriona was in the kitchen. And Catriona saw it.

I was outside on the terrace drinking the cup of instant coffee that might give me the energy to build a pot of the real stuff. She came outside all stiff and controlled and said: ‘I’ve seen a mouse.’

And that was it: the mouse’s fate was sealed. I put in my conscientious objection anyway. I’ve just had a second shot of chemotherapy and want all other living creatures to live as I want myself to live. ‘But it’s a beautiful field mouse,’ I said. ‘Wandered in by mistake probably and might easily wander out again. And who shall blame him when the house is part cave?’

For Catriona my plea belonged in the realm of remote fantasy. ‘Where are our traps?’ she said. Of traps I had no knowledge to offer. ‘Then I’ll borrow Michael’s,’ she said. Discussion closed; verdict in; black cap on. Execution. She emailed Michael immediately.

Michael is a neighbor and naturalist with an affinity to Gaia who makes pottery based on the Palissy model using reptile corpses for molds. He has a live-and-let-live attitude to creatures great and small in his upper story, but draws a line at mice in his kitchen, which he kills. Yes, yes, he could let her have a couple of traps, he replied. He suggested bread for bait. ‘They’ll eat anything if they’re hungry enough,’ he said.

Two spring traps duly arrived in my hand. Hardwood, imprinted with the words LUCIFER and FRANCE and decorated with a line portrait of a mouse with implausibly long whiskers and a malevolent look in its eye. Dark bloodstains near the baiting hook and on the metal clamp testified to the traps’ efficiency.

As we got ready for bed that evening, Catriona said: ‘Did you set the traps?’ With the decorum of servitude I returned to the kitchen and set and baited the four-inch death platforms. One was to go on the floor beside the fridge, she said. For the other I could use my imagination. I placed it at the exact spot where it had paused and I’d sung to it.

I should say here that my arguing for a mouse’s right to life is a fairly new hypocrisy of mine — perhaps the most shimmeringly magnificent of them all. Instead of elaborating, let me just say that for 10 years I was vice-chairman of the South West Lurcher, Terrier and Ferret club. Bushing rabbits with a pair of balletic terrier bitches was what I liked. Later it was ferrets with nets and a catch dog. Compared with ferreting, fox hunting is a branch of Jainism.

At our dog and ferret club summer shows, I would meet elderly hunting folk of one sort or another, a surprising number of whom would candidly admit that with age had come tolerance. Nowadays, they said, they got more pleasure from seeing whatever it was they used to persecute running about unhampered. I’m in that place too.

‘Have you noticed how hard I have tried to control my hysteria over this mouse?’ said Catriona when I came back upstairs after setting the traps. It was true. I had indeed recognized a new, indomitable Roman spirit. She hadn’t mentioned the mouse all day.

Changing with the changing times, are we? I think we might be. Yes, both of us. And why not? ‘You are playing an absolute blinder, darling,’ I said.

This article was originally published in The Spectator’s UK magazine. Subscribe to the World edition here.