Purification is what the Order of the Lantern does with people who show arcane talent. They are taken by the Order for purification. The Order does not say what it involves, and those taken are rarely seen again.
History
Session 2
Iva had been smuggling Brundun, a child with arcane talent, out of Argentum, away from purification.1 She and Temerity argued over what it is. Temerity held that it suppresses magic, and Iva that the purified are executed.1
Session 4
Hazel settled an argument about what counts as magic: if it would earn you a one-way trip to purification, it is magic.2
Session 8
Wellby Emberthumb did not know what purification involves. It is a function of the church, not of the holy texts. His understanding was that the corruption of arcane magic created the Sorrow through the Starfall, and that purification is the Synod of the Silver Flame’s tool for excising that corruption where nothing else will prevent it.3 He could not believe it simply meant the murder of children, and told Temerity she had a responsibility to find out what it means.3
Session 16
Amber Deepdraft did not know what purification means. The Unbound suspected the Order simply killed the mages it took, with no evidence beyond never hearing from them again.4 It might be done at Candlehold: on rare occasions a small caravan leaves the Order’s barracks by the northwest gate, on the road that goes nowhere but there.4
Session 17
Rhea Larnas of the Dragoons of Bahamut told Temerity on 7 Nightdeep, 1714 PSF, after taking her word that it would go no further, that the Order does not execute mages. The belief that it does is simple, and keeps people from pursuing magic, so the Order does not correct it.5 According to Rhea, purification means purifying the Silver Vale, not the mage. There is no way to remove magic, and executing every child born with a natural inclination for it would be cruel, and, more importantly, wasteful.5
Mages, Rhea said, are conscripted: given a choice to fight the Sorrow with everything they have. Those who accept get no rank or title, but fight beside the Order and sometimes the Dragoons, beyond the borders when needed.5 Of those who refuse, she said only that in the fight against the Sorrow, you cannot take its side.5 Magic hastens the Sorrow, but used correctly it is a weapon against it.5 Mages are sent to Candlehold.5 Magic is incredibly rare, and in all her service Rhea had met one or two mages, both loyal comrades who fought the Sorrow in its home as fiercely as any Dragoon.5 She believed what she said.5
Session 18
In a vision on 8 Nightdeep, 1714 PSF, Temerity asked the figure she took to be the embodiment of the Silver Flame whether those taken for purification are ill-fated, or only conscripted, as Rhea Larnas had told her.6 It could not say whether what Rhea had said was true. Purification, it said, is not divine edict, but nor is it wholly uncalled for: the maintenance of order in dire times is necessary to keep the dark at bay, and the method is for mortal kind to devise.6