Phew... this'll take me a few days to write up, I imagine, so bear with me as it is slowly completed.

I'm not sure where to start... You will need to have read Illyria's history and Oralle's history/motivations for this to make total sense, so I suggest you read those.

    * Kentharil, Illyria's half-brother, is disgraced in the eyes of Queen Amlauril. Leaves to study magic in Amn.
    * Despite his disgust for humans, he joins the Cowled Wizards, thinking that he could become powerful within the guild.
    * Realising that the Wizards were too corrupt to even understand, let alone become powerful in, Kentharil started to do plan his revenge on Illyria for stealing his mother away. They would both suffer. Muahahah.

    * Illyria and Kentharil are arguing in Promenade, just after you get out of Irenicus Chateau. Kentharil and Illyria go off in different directions.
    * You meet Illyria in a tavern (Mithrest Inn?), she explains that she came to Amn in search of her parents, that she's from Evermeet, and explains who Kentharil is. You can offer to help her find her family, and she agrees to help you find Imoen, and she joins you, and all is happy and dandy.
    * Several dialogues follow, Illyria learning about the PC. Most responses add 1 to one of the path counters. She suggests <CHARNAME> visit the Council of Six building to find out if they know anything about her parents. Once there, she notices one of her mothers brooches, on a desk, and snatches it off. Inspector Brega says he will look into it for you, but his schedule is tight so you'll need to wait several days.
    * Talks happen. Several days later, a messenger from Brega arrives telling you to come to the CoS building, because he has some disturbing news. Illyria panics.
    * Brega says that Sara and Baran moved in a rush, because their house is extremely messy. He insinuates that he thinks they were kidnapped due to the extreme disorder of the house. He takes you to their house, but now it is completely ordered, like nothing ever happened- Brega swears that it was messy before, and something peculiar is going on.
    * Brega has determined by asking neighbors etcetera that they perhaps moved to Rayen, or maybe the town of Trademeet.

    * Illyria behaves a little strangely around <CHARNAME>.
    * After a period of a few days, Illyria begins to act even worse, even managing to look guilty at times. When asked about it, she finally tells you that she hasn't been entirely truthful with you. She believes that the amulet around her neck, given to her by Oralle, harbours a soul, and refuses to talk more about it.
    * She doesn't talk to you, and if you talk to her she gives you a snippy remark about not knowing when someone needed to be alone. 1 day afterward, she finally tells <CHARNAME> that the soul inside the amulet is of a Beholder... and that it talks to her. If you are a paladin or have Keldorn in the party, this is verified. The answer you give to this is one of the things that will sway her opinion the most; it will add 10 to one of the path counters.
    * More talks follow, about the nature of the amulet, and that Illyria doesn't think Oralle did it on purpose. You also discuss the morality of putting a soul inside an object, and several others things which will by varying degrees affect Illyria's final choice as to what to do with L'Sirr.
    * In the Underdark, the final decision as to what to do with L'Sirr are made.
    * This is where the paths finally come into play. Below are the 4 different paths for SoA, and below them the four different paths for ToB.

Neutral Good Path

    * L'Sirr and Illyria decide that they would like to remain together, at least for a little bit longer. L'Sirr wants to know more of life, and Illyria is intrigued by the enigma that is L'Sirr.
    * L'Sirr tells Illyria that she is indeed 'bonded' to Illyria through an enchantment a powerful mage cast on the amulet, and Illyria wonders who his mysterious mage could be. She instantly thinks Kentharil.
    * While in the Underdark, a merchant is selling magic trinkets and other bits and pieces. In his wares, Illyria notices one of Oralle's intricate hair-decorative pieces, engraved with the older womans name inside. Upon questioning the vendor, you find out it was sold to him by a powerful Drow Matron. Illyria forces you to buy it.
    * During this time, Illyria develops a more refined sense of humour, and begins to speak with Mazzy, Imoen and Jaheira a lot more.
    * L'Sirr says she senses Beholder's nearby, and when Ardulace commands the party to bring her the eye of an Elder Orb Illyria and L'Sirr are furious, and after you get out of the building Illyria has a bit of a rant at you.
    * L'Sirr and Illyria promise to aid you for as long as you need if you would leave the Beholder's alone. L'Sirr may not like them much, but she still feels a need to protect them.
    * Illyria will leave the party if you attempt to get the eye of the Elder Orb. Once you have the blood of the kua-toan prince everything proceeds normally.

    * Once back on the surface, the Sages sense something horribly amiss with Illyria, saying that she is tainted with darkness. You convince them that she is no threat, but they say that if she causes anything to go wrong, she will be hunted down and killed.
    * Once you're out of sight of the elves, Illyria thanks you for standing up for her and L'Sirr, and tells you that it means a lot to them both. She asks you to go to the Council of Six building to find a map, so you can investigate the possibility that they moved to Rayen.
    * Brega adds it to your map, and mentions that he did a bit of research on the people connected to Baran and Sara. Illyria immediately thinks of Kentharil, and Brega nods, saying that he was a somewhat powerful member of the cowled wizards, but he abused his position. The Cowled Wizards are after him, though Tolgerias refuses to talk to you about it.
    * Travelling to Rayen, you stop for the night. Around the campfire, your party members discuss some stuff, and Illyria tells you all about her bitterness about Baran, and how she was both dreading and being excited about seeing her parents. Some banters between NPCs. Around 5 banters in all.
    * Arriving in Rayen, you ask around and find out that Illyria's parents live a little away from the village itself. Some of the villagers remark about them warmly, others less so.
    * You meet Saranan on the way to the house, on the forest path. She is absolutely shocked and extremely happy to see Illyria, crying that she didn't think she'd ever see her again. (Screen goes to black
    * Back in the cottage, Saranan speaks to Illyria about what happened to them, how they were forced to leave Amn by the Cowled Wizards. Illyria growls softly and tells her of Kentharil, and Saranan is shocked. It is at this point when Baran enters.
    * Awkward situation ensues, Illyria isn't sure how to react. She makes a bitter remark about how he 'abandoned' her, and Baran almost breaks down. He tells her of his and Sara's battle to stay on Evermeet, and how only Illyria and Sara had been allowed to stay. Illyria feels horribly, horribly guilty. Apologises muchly. Crying ensues.
    * The next day, Sara and <CHARNAME> go on a short walk through the forest. Sara tells <CHARNAME> how thankful she is. She says she knows that there is something bigger going on, and that Lyr needs to leave soon. Back in the house, everyone says goodbye and prepares to leave.
    * After you leave the house, Illyria thanks you profusely. L'Sirr, surprisingly, also does. Illyria smirks about something but won't tell you what it is.

    * Another messenger from Brega tells you that Kentharil has been apprehended, and to be executed in 2 days time. This forces Illyria to take a step back, and think about Kentharil's situation. He also asks that you come to see him as soon as possible to arrange the funeral and inform any family members.
    * When you arrive at the Council of Six building, Brega asks you to come with him to somewhere more private so you can speak freely to each other. The place in question is a room out the back, which is guarded from all forms of scrying, divination, and technological means of eavesdropping. Brega tells you that he believes that there is something wrong with Kentharil's story, and that perhaps he wasn't working alone, or maybe that he was simply a pawn or puppet. He asks that you relate to him any information you can to him regarding the case urgently, and takes you back to the front of the building.
    * There, Illyria tells of her feelings about the matter; how now that she thinks about it Kentharil wouldn't abuse his powers simply to get revenge on his mother, no matter how bitter he was. She has no idea what she can do, though, and it frustrates her a lot.
    * Illyria worries that she won't be able to get the message to her mother, but L'Sirr says that she'll handle it and with a supreme effort transports herself and Illyria to Rayen. She comes back in a minute or so, saying that Sara will come as quickly as she can.
    * Finally the day arrives and you are summoned to the Council of Six building, where you are to speak with Brega. Sara is there, and she also believes that Kentharil is somehow innocent. But, once again, there is no way to prove it.
    * Brega sadly takes them to a small cell where Kentharil is, for them to say their final goodbyes. Kentharil refuses to talk to any of them, simply stating that they abandoned him and he wasn't going to forgive them now, in his time of greatest need, when they will just betray him further.
    * You are taken to an execution ground, and Kentharil makes one last plea for his life. Illyria starts to cry, and apoligises for not being able to save him, and for once in his life he forgives her. He is killed by decapitation.
    * Afterwards, Illyria is numb. Sara leaves, but Illyria is unresponsive. She has a 'blank' look to her, like she is completely oblivious to everything happening to her. You can approach this from several different perspectives; you can tell her to snap out of it, it couldn't be helped, or you can comfort her and tell her it wasn't her fault. Either way she snaps out of it, and apologises.
    * Everything is normal after this point, you have a few dialogues where Illyria half-regrets her feelings about Kentharil, and you discuss Oralle a bit.