The police station at Tak Bai, a small town near the Thai-Malaysian border, looks deceptively ordinary.
Survivors were packed into trucks in layers
It is hard to imagine the chain of events which began here last October and ended in the deaths of 85 local Muslims.
A few bullet holes in a nearby wall are the only sign that something terrible happened here.
An eyewitness - too afraid to give me his name or even the name of his village - told me what he saw.
When over 2,000 Muslims demonstrated outside the police station, the Thai police and army responded with water cannons and gunfire.
Then the soldiers bundled hundreds of Muslim men into trucks, four deep. By the time the trucks reached an army base further north, 78 of the men had died of suffocation.
What made the event even more shocking to local Muslims was that it occurred during Ramadan, the Muslim month of fasting.
It was the bloodiest moment in a year of violence, beginning in January 2004, which has claimed over 500 lives - and thrown a spotlight on one of the world's largely forgotten Muslim minorities.
From harmony to hatred
Thailand is an overwhelmingly Buddhist country where Muslims are less than ten per cent of the population.
There are Muslims in the north and centre of the country, but in the three provinces of the deep south - Pattani, Yala and Narathiwat - they are in the majority.
Until recently, Muslims and Buddhists lived side by side in the south in relative harmony.
Now civilians on both sides are being killed and the mood is one of bitterness and mistrust.
So what's gone wrong?
As I travelled through the south, I felt I was trying to unravel a mystery.
There seem to be three underlying factors fuelling the Muslims' sense of grievance.
They believe their history and culture are not acknowledged. For centuries, Pattani was the centre of an independent Muslim kingdom - the Pattani sultanate - which was only incorporated into the Thai state in the early 20th century.
They feel economically marginalised. The south is one of the poorest parts of the country - drawing little benefit, for example, from the country's successful tourist industry.
Thanks to globalisation, they have much stronger links with the wider Muslim world - and share Muslim anger over such issues as Palestine and Iraq.
Bloodshed at the mosque
But much less clear is who is behind the recent violence.
Take the events of a single day, 28 April last year.
I visited the ancient and revered Kru Se mosque in the town of Pattani, where 32 Muslim militants were killed by the Thai security forces after a nine-hour standoff.
But the drama at the mosque was only the climax of a day of violence which claimed over 100 Muslim lives.
In a series of apparently co-ordinated incidents, Muslims attacked police posts across the three southern provinces.
It was the bloodiest day of fighting since violence resurfaced in the region in January
Given that they were armed only with knives and machetes, these were virtually suicide missions.
But who these militants are, and what drives them, remains a mystery.
I asked Nur, whose husband Mohammed was one of those who died on 28 April, why she thought he had done it.
He just went off one day, she said, and didn't return. Even now, she has never seen the body.
Experts can shed some light on the puzzle, but not much.
They believe an older separatist movement - active in the south in the 1960s and seventies - has now been superseded by a newer Islamic one.
Government advisers in Bangkok go further and allege the involvement of Jemaah Islamiyah, regarded as the regional arm of Al-Qaeda.
But they offer little by way of proof.
Fish and fertilisers
"The people love the army," I was assured by the military spokesman in the south, a smooth-talking man known as Colonel Sam.
In an effort to convince me, he took me to see smiling villagers who'd received fish and fertilisers, as well as protection, from Colonel Sam and his soldiers.
But virtually all of them were Buddhists - the Muslims, I was told, were praying at the mosque.
In one village Thai flags had been placed every few metres along the roadside.
Colonel Sam gave the villagers a pep talk, urging them to show the BBC how strong and united they were.
It all felt rather staged.
A wider insurgency?
The reality is that the Muslims of the south deeply resent the Thai army and its pervasive presence.
Thanks to the events at Tak Bai, the militants now seem to enjoy more grass-roots support than before.
In national elections on 6 February, Prime Minister Thaksin Shinawatra won a landslide victory and four more years in power.
Most experts think he has mishandled the conflict in the south.
The danger is that, if his government sticks with its hard-line strategy in the south, the insurgency will be transformed from a local problem into a regional or even an international one.
Roger Hardy's programme on Thailand - the second in a four-part series, "Islam's Furthest Frontier" - is broadcast on the BBC World Service on 14 February.