Illona Rider was a baby when she was found by the Travelers (singers and storytellers) in a town that was raided and burned down by bandits. Since the village was in the Ardais Domain, it is very likely she is the nedestra daughter of Kennard-Dyan Ardais. Upon meeting her, he was shocked of her resemblence to Eduina MacGarret, a young woman he had a daliance with.
While she and Domenic Alton-Hastur were young they met during a Terranan plot to kill Mikhail Hastur and the rest of the Comyn Domain heads during the funeral of Regis Hastur. The two became friends and were students together at Neskaya Tower for a few years. It was there that Illona discovered she had incredible talent, she possessed the Alton Donas and went on to become Under-Keeper at Nevarsin Tower under Silvana, who Lew Alton believed to be the missing daughter of Regis Hastur.
After a few years of separation, when she and Domenic re-met, they were drawn together as more than friends and soon became lovers, despite his vow of marriage to Alanna Alar. He even proposed to Illona but she told him he must be true to his promise and she would rather be his lover and be independent to pursue a path within the Towers.
During this time a dreadful disease was spreading through the countryside which had people dying and flocking to Thendara for help. Illona and some of her Tower circle tried to heal a man at St. Valentines of the Snows but the man died; after some research she was sure it was a new flare up of Trailsmen's fever. Accompanying Domenic and his grandfatherLew Alton to Thendara, she realizes how wide spread the disease is. Since it is Council season, Illona and a contingent of Keepers are able to help find a cure for the disease.
At the end of that adventure Illona, is asked to be Under-Keeper at the newly reopened Comyn Tower and becomes Domenic's freemate.