Arach - Tinilith Arach - Tinilith was the clerical school in the drow city of Menzoberranzan . Like the rest of the Academy , it was located in Tier Breche . Structure . The complex - - the largest of the Academy - - was located on the northern side of the Tier Breche cavern and was shaped like a spider . The " cephalothorax " of the spider housed the grandest chapels , the holiest altars , and the quarters of the senior priestesses . The crowning gem of the complex was a the main chapel , carved from a single mass of black stone . Inside , seats surrounded circular platform that held a statue of spider with the head of drow female . The Mistress of the academy had an office on the highest level that had a tapestry depicting Lolth looming over a sacrificed surface elf . The Mistress also wore a brooch that allowed her to unlock all doors in Arach - Tinilith . There were dungeon - like kitchens located in the lower levels . Slaves , such as the ogre slave Chirank in 1361 DR , were employed there . A small library was located somewhere in the complex . History . Arach - Tinilith was founded as part of Tier Breche , Menzoberranzan ' s educational institution as House S ' sril ' s literal last act , in order to standardize Lolth ' s teachings and produce cleric s of any meaningful quality . The House was one of Menzoberranzan ' s founding Houses and died of naturally for not having heirs . Before the founding , it was normal in Menzoberranzan for each House to teach only their own children . House S ' sril saw , that this practice only led to the production of bad divine spellcasters as wells as to numerous different interpretations of Lolth ' s teachings . In 1372 DR , the Mistress of Arach - Tinilith , Quenthel Baenre , was attacked at the school by a number of demons intending to assassinate her . A number of novice priestesses and even instructors led by Drisinil Armgo believed that Quenthel had lost he favor of Lolth , and thus they planned to murder her . Quenthel discovered their plot and summoned hordes of spiders to kill them and demonstrate that she was in her goddess ' s favor ( although that was during the Silence of Lolth ) . In truth , unbeknownst to her , the demons had been sent by her brother , Gromph Baenre , the Archmage of Menzoberranzan . In 1469 DR , members of the Jaezred Chaulssin infiltrated and tempered with the graduation ceremony . It caused a large number of demon s to be summoned , who then ran amok causing heavy damage , not only to the temple ' s structure but also in a lot of lives . Schooling . Most new priestesses ( called novices ) had to share rooms with one or two others until the fifth year ( although Liriel Baenre was able to secure her own room ) . Novices wore black robes with red trim . Each day ended in the chapel in prayer and praise of Lolth . Priestesses received training in weapons combat from older students of Melee - Magthere . Inhabitants . All female , the priestesses of Lolth went to Arach - Tinilith after being trained by their houses in the basics of worship of the Spider Queen . This usually happened around the age of 40 , and they were to spend 50 years studying under the tutelage of the mistresses there . By 1361 DR , it appeared priestesses were expected to enter Arach - Tinilith by age 25 . Priestesses helped fulfill the duty of Arach - Tinilith and the Academy by enacting healing spells , serving as part of the guard of Menzoberranzan , praying to Lolth to keep the city in her favor , and providing religious instruction to other students of the Academy . It was a crime for males to enter Arach - Tinilith unsummoned . Notable inhabitants of Arach - Tinilith . Matron Mistresses / Mistress Mothers . The Matron Mistress was often addressed as " Exalted Mother , " a title also used for matron mothers .