Adventus Consilii was raised in Evasendia by Lem's second—and some say least talented—student, Consilii Exspectans. She did not get along at all well with the Lemmite apprentices closest to her in age, Tresmillia's daughter Penipotens Sine Alis and granddaughter Quadra Casta, and consequently spent most of her time in the company of her master, who came to rely on her for so many things that some on the Council joked that it was difficult to tell which of them was the teacher and which the pupil: a statement which perhaps haunted Consilii Exspectans more than anyone realized at the time.
She left Evasendia with north-bound diaspora party in 232 and joined her parens in founding Covenant Brellyn early the next year. In her time there, she quarrelled constantly with the descendants of Tresmillia, disagreeing with them on everything from the proper interpretation of the books of Lem to the proper administrative procedures for running a covenant. Although she felt duty-bound to support her parens Consilii in his struggle over the next two years to define his own interpretation of the Books of Lem, she was not satisfied by his insights, and it was likely due to her lackluster feedback that he never published or distributed his early drafts.
She found what she was looking for in 235, when Lem's third student, Quae Montes Cieret, came to Brellyn to share her own insights into the Books of Lem, derived in part from her experiences in Chaeronia, where she had travelled with the rest of the north-bound party to found Covenant Trismagisti. Adventus was very enthusiastic about Quae Montes' work: she declared herself a convert immediately, and her parens followed suit shortly thereafter. They left Brellyn to found Circulus Ruber in the mountains of Chaeronia later that year.
This was the first time in her life that Adventus had not been forced into close proximity to her close age-peers Penipotens Sine Alis and Quadra Casta, and she found that distance improved her feelings towards them tremendously. Although she was to carry on lively theoretical debate with the Brellyn Lemmites for the next thirty-five years, she became in time quite friendly with her primary antagonist, Quadra Casta, to whom she wrote a surprisingly tactful note of support when Quadra Casta's only student converted to the Gravite doctrine in 257. This may, however, have been merely quid pro quo: unlike several others among the Brellyn Lemmites, Quadra Casta had never expressed any sentiment which even the most paranoid observer could have mistaken for the merest hint of a gloat when the Order had learned of Consilii Exspectans' death in the swamps of Orsa a decade or so earlier.
Adventus was often thought to be the only person even to come close to comprehending some of the more arcane and baffling utterances of the Circulan School's eccentric founder, Quae Montes Cieret, and in later years, as Quae Montes became increasingly obscure, she was often to serve as a kind of translator for the founder; some say that even Quae Montes' own student was sometimes forced to rely on Adventus to understand what his parens was trying to tell him. By the 260s, she was the pragmatic, if not the spiritual, leader of the covenant, and she was seated alongside Quae Montes Cieret as representative of Circulus Ruber on the First Tribunal in 269.
One of the most vocal supporters of investigations into Eleanorean theocratism on the Tribunal, both Adventus and her student Laura Insolita gave formal testimony against the magi of Covenant Trismagisti, and she was also to send for some of Circulus Ruber's covenfolk to support and add to her testimony. Although she herself did not join with Lem and House Savacion in the hunt for Eleanor, remaining seated on the Tribunal until its dissolution in 271, her students did join with them and were also among the destroyers of Covenant Trismagisti later that year. Upon her return from Annalum in 271, she announced that it was time to ensure that the Circle was "cleansed," and initiated a purge of all of the covenant's folk who had ever had any dealings at all with the Trismagistans, with any members of House Eleanor, with any members of any suspect covenants, or with any suspect magi. As the Trismagistans had been close neighbors with a keen interest in inter-covenant cooperation, there were quite a lot of them.
Revelations of the Trismagistans' theocratic designs on Pandrell seems to have made quite an impression on Adventus. In 275, when Quae Montes Cieret fell into the Twilight state in which she was to remain for the rest of her life, Adventus interpreted one of her enigmatic riddles to indicate that the "circle" of the Red Circle for which their covenant was named was actually a sphere with its center point in the theocratic stronghold of Pandrell itself, and that the covenant's mission was to guard and to shield this circle against those who might try to use its power. Under her direction, over the next twenty years the Circulans established an elaborate system of surveillance around the mountain, and they also instituted a policy of quietly yet ruthlessly exterminating all non-Cholaeic magical practitioners who fell within the boundaries of the circle they had defined. The Circulan founders of Quintus Opacus were heavily influenced by this policy: most of them had spent their younger years enforcing the purity of the Red Circle.
Always exceptionally conservative about her dressing practice, Adventus refused to don the blue until the disappearance of Quae Montes Cieret in 287, and although she was finally granted access to the Indigo Book in 293, only two years before her death, she would never wear the color. Her younger filia Laura Insolita was later, while a member of Quintus Opacus, to claim that in her parens' last days she had prophecied the dissolution of Circulus Ruber and the founding of Quintus Opacus as the natural successor to its mission. Many within the House, however, have expressed doubts about these claims: if Adventus' last words were such clear prophecies, they wonder, then why on earth did Laura never mention them until these events had already come to pass?
She taught two students:
- Caprifica Montis (L15), from 236 to 251
- Laura Insolita (L22), from 255 to 270
