Mexico's drug gangs have long caused scenes of carnage on the streets of some of the country's border cities, but the violence is spreading to many areas that used to be safe.
El Cercado is a sleepy village in the foothills of the Sierra Madre.
It is situated about half an hour's drive south of Monterrey, Mexico's third largest city.
Drug warfare has affected even rural areas
In contrast to the pine forests and alpine meadows on its western flank, the vegetation here on the eastern side of the Sierra is tropical - lush and intensely green.
Four years ago I was lucky enough to spend a little time in El Cercado.
My aunt Blanca and uncle Juan invited my mother and me to stay in their weekend retreat - a spacious old ranch, crammed with family bric-a-brac, with a terrace running the length of the house.
We would sit in rocking chairs listening to the birds and contemplating the view.
Each morning, before the sun was too high, we went for rambling walks along dirt tracks that criss-crossed the hills above the house, returning before the heat of the day to rest in the shade.
At night we would roast meat on the barbecue, and spend hours around the card table, a glass of tequila in hand.
Above all, that house was a place for family.
Living in fear
So when I returned to Monterrey this summer and learnt that Blanca and Juan's daughter was soon to be married, warm memories came flooding back.
"Will the wedding be held at El Cercado,?" I asked enthusiastically.
The gangsters set up roadblocks at night - they stop people, rob them, and sometimes kidnap them
My uncle looked both surprised and dismayed in equal measure.
Alarmed by his expression, I wondered if perhaps I had revealed some crass misapprehension of Mexican wedding protocol.
Perhaps the house was considered too "basic" a venue for a wedding reception.
I was unprepared for his response:
"Oh no, we don't go there any more. It's become far too dangerous," he said.
Unprompted, he began describing how life has changed in Monterrey.
"We hear gunfights regularly. The gangsters set up roadblocks at night, even on the main roads. They stop people, rob them, and sometimes kidnap them," he said.
"There will be a shootout, then 4x4s will turn up afterwards to clear up the bodies, as if nothing's happened," he told me.
"And the police," he went on, "Where are they? They're nowhere to be seen! We're on our own here, and we need to start thinking about arming ourselves."
The next morning I thought that perhaps Juan was being overly pessimistic.
I tried asking Elena, Blanca's sister - the sunniest person imaginable.
"You know what they found up there the other day?" she said, referring to the Cerro de la Silla - Monterrey's distinctive saddle-shaped mountain.
Two abandoned cars and a severed head.
Mexico's drug wars are notoriously sadistic. I recently read of one drug murder in which a man's face had been flayed off and stitched to a football. And there was the incident of the head that was rolled on to a dance floor in the state of Michoacan.
A term I have now become familiar with is narcofosa: The communal grave into which the drug barons dump the bodies of their victims.
Elena told me of one that had been found in Monterrey.
Mexico's police are trying to curtail the drugs cartels
Fifty or so bodies, not even decomposed. In other words, fresh.
"No-one goes out at night any more," she said.
"Not even the youngsters are going to clubs. They're too scared."
Later, as we drove through the city by day, Elena showed me a few local landmarks - the university library building where two students were gunned down in a case of mistaken identity, the supermarket where a police informer was shot dead as he sat in his car.
"He was on the phone," said Elena. "He should have been a little less obvious!"
Of course, I had been aware the violence was worsening in Mexico, but I realise now that I had made a few assumptions.
First, that it was principally in the border cities: Tijuana, Ciudad Juarez, Nuevo Laredo.
Second, that when there were killings elsewhere, they were self-contained, targeted assassinations of people involved in the trade.
I had totally underestimated the extent of the violence, how it is hampering people's lives and curtailing their freedoms.
Another friend told me of a recent visit to Torreon, west of Monterrey.
She too described city streets deserted after dark, with no-one venturing out.
A couple of days after that conversation, 17 people were murdered at a party in Torreon, the third such massacre this year.
It seems particularly sad that this is happening in a country that 10 years ago made a triumphant return to multi-party democracy, and which this year celebrates its bicentenary.
Juan and Blanca hope that their newly married daughter and son-in-law will leave and go to live in the United States, where their son and other daughter already live with their families.
For as Juan pointed out, as long as demand remains for the drugs and as long as the cartels can cross the US border and buy whatever weapons they desire, the war seems bound to continue.
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