The top commanders of the security forces and their multiple junta supervisors marked the first anniversary of the Erawan Shrine killings with a re-enactment of the investigation of that 2015 atrocity, using the Mother's Day attacks in the South as the example.
As barn doors across the nation slammed shut in official panic after the horses bolted during the unprecedented day-long explosions, the military, police and intelligence agencies launched searches with the same careful coordination and forensic detail that played such an important part in last year's probe.
Last week's highlight came on Wednesday when the military detained and presented to the media 15 men and two women said to be prime suspects in the investigation. It seemed the strangest group of alleged bomb plotters ever seen in a rogues' line-up.
The immediate jaw-dropper was the ages of the new revolutionaries. The most sprightly is 39. The average age of the group is more than 58 years and two months, and two of the males are 71. Not only do they comprise a demographic of every old people's home in the country, they could if they wished organise next year's Every Region of Thailand expo. If there was no trace of youthful energy on exhibit, there was diversity that included every region of the nation.
It was like the charts police presented last August showing what they said was a 37-member Erawan Shrine bomb gang, except for how much older the alleged Hua Hin-Phuket plotters were. And then, in an Erawan-like move, security officers announced that the 17 detained people weren't actually bombing suspects, they were old communists picked up in some other completely unrelated investigation.
The air went out of the room, leaving only exceptionalism to breathe.
As with last year's Erawan Shrine investigation, the second week of the Mother's Day plot probe centred on the deep South. Deputy Prime Minister Prawit Wongsuwon said he had a completely open mind except it wasn't any of the gangs from the deep South. Others disagreed and laid out the case.
The murderous Mother's Day plot was well organised, tight-knit and, despite gaffes like unexploded devices, very successful in the eyes of any terrorist. Authorities from top to bottom had absolutely no clue it was going to happen, where "absolutely" is an absolute word.
Consider. A bombing spree gathered more than 20 devices in more than a dozen places in seven towns, all planted pretty much at once and all exploded in a continuous string that caused officials and people to become jumpy and then panicky. That takes quite a lot of planning and manpower along with a modest amount of cash, plus not one person tipped off one policeman or soldier or town gossip.
That is so phenomenal that it raised recollections of the 2006 New Year's Eve bombs in Bangkok and last year's mall car-bomb at Koh Samui. In turn, that resumed suspicion that a well-oiled and tight-knit group was involved, and such groups definitely exist in the deep South.
Investigators named two. One is the extremely violent Barisan Revolusi Nasional (BRN, National Revolutionary Front), which has been shooting, throwing bombs and beheading people in the southern provinces for 53 years. Irony alert: In addition to trying to kill, maim and terrorise enough people to separate from Thailand, the BRN also is the "peace partner" of both this and the previous government.
The second group, a far less credible suspect in anti-military, anti-tourist, anti-royal bombing, is the Wadah Faction. It is the creation of Gen Chavalit Yongchaiyudh, that old (84) wizard of the paramilitary who finagled so many 20th century political paramilitary operations, and created Wadah from nothing to give himself Muslim political support.
It's an interesting suspect, the Wadah Group. Ageing ex-minister Wan Muhamad Nor Matha of Yala is no separatist and always has stressed political over violence. But the group suddenly became rejuvenated in July over the referendum. It pointed out vociferously and continuously how Buddhism has been elevated in the new charter compared with past constitutions, to what it claims will be the detriment of other religions, first and foremost Islam.
In the referendum, deep South voters rejected the charter and spoiled twice the ballots of anywhere.
The police expertise with DNA resulted in an arrest warrant for veteran rebel Ahama Lengha, a man not on their investigative radar since 2006. Police matched exploded bomb DNA to Mr Lengha even faster than their DNA successes at Koh Tao.