It’s a good month for nuns. Like spiders, they seem to like the autumn and come out fattened up and swishing by, up to their mysterious business and appearing and disappearing like municipal nudibranchs. It’s a good season for sisters. I’ve been very lucky with my nun-coursing of late. You have to be completely prepared for a nun’s arrival, ever watchful for their sudden appearance. I caught sight of a shadowy Poor Clare and a Rassophore (a very rare nun – the lesser-spotted Eastern Orthodoxy – not usually seen so far south).

Nuns pretend to be static, hidden away behind the walls and shutters of their convents, singing and reciting the Liturgy of the Hours or contemplating their solemn vows, but this is not the case. As any seasoned nun hunter knows, they move at the speed of the universal constant, defying Einstein with their own version of mass and being the harbinger of nonchange. My grandmother said, “Where angels tread, trouble follows”.

A Pentecostal evangelist with a taste for glossolalia, my grandmother had a soft spot for nuns, sighing whenever she saw one on TV and asking if any of us had seen any, where-when-how they were dressed and 100 other questions, with our affirmative answers rewarded with an extra slice of Battenberg and her reaching for her nun notebook to scrawl the new intelligence down. She entered into and carried on a 50-year correspondence with the Mother Superior of the Philadelphia Convent for Fallen Branches, Blessed Mother Abbess Euphemia.

Every year on her birthday, my grandmother would receive a small brown parcel and, making herself secure with a glare, would stomp off into the front parlour, where the sounds of ripping paper, delicate laughter and scoffing would leak out into the silent, dark back kitchen where my sisters and I would huddle waiting for the explosion. It always came. A protracted low moan would issue from under the door, then the sound of her chair being tipped over and my grandmother would appear, crying and red in the face, looking like she was going to make us eat our tea in the coal bunker. She’d be grinding her gums together and letting out short puffs of breath, like a malevolent bull leaning on an open gate.

My sisters and I would gasp as my grandmother’s full fury was efficiently dispatched on getting the remains of the box into the fire. Letters torn to confetti, cake wrappers and the shredded rags of some small item of what might have been a bandeau all burned up as she lurched over the flames, pumping her old leather bellows with all the verve of a puppy drowning. Peeping over her glasses and ominously commanding us to “never trust a nun”, she ushered us out. I crept back in that evening and, in the ashes, found a tiny charred heart-shaped cameo locket of a young nun’s smiling face surrounded by ivy.

Ivy was my grandmother’s name. It’s a family peculiarity, to be exquisite and never explain…