A long time ago, there was an orc tribe deep in the North. Legends say they were Izrador's best servitors, the most vicious and cruel, led by implacable kusaratch udareen. Yet they never received a word of praise for their actions; worse, too often did the Order of Shadow take for his own their achievements.
By the end of the Second Age, Grormarg, the kusarach udareen of the tribe, was in open conflict with the legates because of the high competition for power between the Dark God's minions.
When the Last Battle of the Second Age ended, the White Mother Tribe had successfully slain one of the Dragons that had come from the South to oppose their northern brethren who had been seduced by the Shadow. Klirxci was only mortally wounded, though. Cut from their supply lines because of the aftermath of this hard fought battle, the tribe had not eaten anything for weeks. This large amount of flesh was a great boon for them. But Ikar the Legate, one of the few surviving humans, forbid the orcs to eat such meat, for Izrador had forbidden it. Grormarg was upset: surely Izrador would not let perish such brave combatants who had served him so well? And she decapitated Ikar with her vardatch.
That night, all the tribe dined of dragon meat, and Grormarg ate the dragon's heart. Then she dreamt and saw the future. She saw the orcs invading all of Eredane. She saw the dwarves bathing in their blood and the elves savagely tortured. She saw the humans enslaved and collaborating with the Legates.
And she saw that Izrador would destroy his creatures when he would have conquered the world and would not need any more fighters.
She saw the dark mirrors finally draining the world's magical energies but eventually this would not grant Izrador enough energy to tear the Veil. Instead, the Dark God would use this energy, not for his Ascension, but to absorb the land's life energy, killing all living creatures in the process. Only then would the Shadow be strong enough to break the Veil.
And she saw Izrador ascending to Heaven from a cracked and deserted, lifeless world. When she woke up, she knew with absolute certitude that her vision was true. Klirxci was reputed for her prophecies, and this was obviously an unexpected gift from the dead dragon to its slayers. She then gathered her closest followers and told them her dream. Those who denied it were quietly later assassinated. And those who saw her wisdom were gifted with an injection of the dragon's blood, and gained its clairvoyance. They secretly killed all other members of the tribe in their sleep. The White Mother Tribe was no more. The White Mother Sect was born, and no one knew it. Grormarg's followers scattered to the winds, and each one was eventually adopted into another tribe. There, they cautiously probed for like-minded orcs, and perpetrated small scale, risk less sabotages, in an effort to delay Izrador's war effort. But they maintained their cover above all, mercilessly killing innocent dwarves and elves in the process. When they were respected as warriors, they were listened to as sages of their tribes. And then they discovered potential recruits, those who keep their temper even in the thick of battle, who seemed to be the most cunning and intelligent of their tribe. Thus the sect slowly grew in numbers and never was detected.
The Sect's goal is the preservation of the orcish race. They realize that, as Izrador is closing on his agenda, their days are counted. Each mirror will soon silently kill all forms of life, as magic is what sustains the land with life energy. Orcs are also a lifeform and thus are threatened too. If they have not yet figured out how to prevent this, they nonetheless can slow the process by sabotaging dark mirrors, and slowing Izrador's armies advance (figuring that, the more terrain the Dark God wins, the less use are the orcs to him). Most orcs in this secret society are still of an evil alignment: they still want to conquer and rule the world, but they do not wish to perish in the process, serving a god that will eventually betray them. They reason that, if they ever find a way to deal with Izrador, then they will attack the other people of Eredane. But first things first... In order to defeat the Shadow, they'd like to find allies and support, but realize that everyone hates orcs. So far, only a few good-aligned individuals managed short-terms alliances with small resistance groups. There are a few good aligned orcs in this sect, who actually are deserters in Jahzir's SOuth army who softened in the contact of peaceful (or scared and obedient) populations and abundant resources, and realized it was not possible to sustain themselves in the long term through pillage alone. They often became themselves farmers and hunters, and protected small halfling or human communities with whom they traded goods and food. Others, originally bandits that were hunted down by their fellow orcs in the eastern mountains, eventually reached mutual protection agreements with some kurgun clans. A few were even recruited into the Durgis Clan.
Each potential adept is abducted on the pretence of a "solo mission" with the aging sect member (who is at the time a respected elder warrior of his tribe) and led to the kusaratch udareen of the sect, who reads his alignment and determines his loyalty and the sincerity of his engagement to the orcish cause. If he does not pass this test, he is executed. When adopted, he is infused with the blood of one of the members (who is usually executed in the process; orcs do not live long anyway). They are then sent back into their tribe, where they can pursue their mentor's work.
The White Mother Sect members are given specific training during the few times they can have access to elder members. This usually allows them to secretly gain levels as rogues, eventually giving them the opportunity to join two PrCs: "Avenging Knife" (well, the orcish equivalent), and "Mirror Breaker" (as in Against the Shadow and the ToS vol. I respectively). Some limited agents also have a few contacts with the Durgis Clan (this is their biggest secret). But the most unexpected and reliable allies are halfling slaves who eventually become trusted to a White Mother Sect member: those make wonderful support, as they have access to all sorts of information (who cares what is said in front of a slave who could as well be a piece of furniture?), and to all sorts of places without attracting undue attention (and therefore can perform all kinds of sabotage, thus providing ample diversion for the orc). Oh, and they also be good alibis ("Oh, Sir Legate, I can assure you that my master was with me when the barracks took fire"). The group's most powerful resource is their kusaratch udareen. Since they broke away from Izrador, they no longer have access to his magics. Instead, they replaced it with the orc's ancestral shamanism (which they practiced before Izrador took his "mother-wives" and gifted them with his dark blessings). There are only three of them at any given time (usually one mistress and her two apprentices). They usually are Chn10/Drd10 (with a focus on necromancy spells), and create charms for their agents (as hose are undetectable magic items) and all sorts of potions to help them in their missions. The Sect's main cell lies in a small village, deep in the southern Erenland, far from civilization. It was originally an orcish deserter's village, but soon the kusaratch udareen and their warriors settled there, slaying those who would not embrace the sect's philosophy. This village is hidden not only with powerful illusion spells, but also because the sect has a secret agreement with a cunning traitor prince, who plays a subtle double game between the occupying forces and the resistance (his name is Kular, and no one has yet determined what side he will eventually choose). As there are orcs in Erenland for a century, the Sect has discovered that, as more and more orcs come in the better lands to settle there, they seem more and more perceptive to their opinions, as if, by becoming geographically distant from izrador, they were escaping his influence... (this is also known by the legates, who are quite alarmed at this, but who try and keep it a secret)