She did not cooperate, and was therefore considered a betrayer. Necessarius wants to capture her and find a way to weaken and perhaps destroy the Dawn-Colored Sunlight. Even though she is not directly involved with the cabal, it's highly possible that she is valuable in areas related to the cabal. Even though she doesn't know it, magicians from the Dawn-Colored Sunlight have been positioned around her to watch and protect her. The woman on the phone told Stiyl that Patricia has absolutely no knowledge of magic, but her sister is the leader of the Dawn-Colored Sunlight. He was told that the betrayer is a girl named Patricia Birdway, and from the descriptions, it was clear that the girl in front of him was Patricia. Stiyl then received a call from the Necessarius. The girl even thought Stiyl was Theodosia's ally, and asked him to help Theodosia by calling Anti-Skill. It was clearly the reaction of someone who has no knowledge of magic. Stiyl was prepared to fight, but the girl's reaction was unexpected. He went in, saw a 12-year-old girl kneeling on the floor and also Theodosia lying down.
Then Stiyl went to the room which was supposed to be sealed by Theodosia. Theodosia was defeated, but she used a magic to escape. However, as a fire user, Stiyl already has the Ehwaz rune on his shoes, and it represents a horse, which allows him to "jump" over fire. By throwing the matches, she can trigger explosions. Her matches have 2 symbolization embedded - Skirnir's Staff (which has the role of stealing) and fire in Iceland (which has the role of protecting). Then they start fighting immediately after. At first Stiyl thought the betrayer hired magic cabals as bodyguards, but then Theodosia told him that she is actually the betrayer's accomplice.
Theodosia also told him that the betrayer has accomplices.
After entering Academy City and settling down, he decided to go for a smoke while waiting for further instructions. Then, he received instructions to go to Academy City for the next job. He just completed a job and killed 19 people from a magic cabal. The guys chasing Touma thought that he took their boss as hostage. Naturally, Touma carried the girl in his arms and ran away with her. They discovered Touma and chased after him. Touma overheard their talk on the way home from grocery shopping.
A bunch of people were about how the preparations are finished, and now they're just waiting for instructions from the boss.