Here's another, shorter example of what I'm looking for.
You approach the gith Patrol. It's night. Ominous roar. "What the heck was that?"
"Dragon," says Lae'zel. "My kin are near."
Shadow of dragon created in moonlight seen on the ground. Ominous music begins.
Gith sequence happens at night (well potentially if you choose to travel by night). Dragon lights up the area with flames and lands.
You approach. If Shadowheart is with you, she suddenly refuses to go any further, and before you can say anything, she flees. You have the option of another character to add instantly to your party to replace her, or you can choose to go after her.
You replace her. Voss determines you must die but uses Detect Thought. "Ah! The weapon is in the hands of their cleric companion. Beretha. Kill them. Quedenos! To the sky. We will find their companion and retrieve the weapon.". And THAT'S why he leaves. He goes after SH who has the weapon.
If you go after SH instead, she absolutely refuses to go with you. Lae'zel, however, demands that you go. You must choose. Who will you listen to? Whoever you choose might impact your relationship and so forth.
The point: solid reasoning for why Voss leaves and also creates tensions in the party. Kinda like how Jaheira and Aerie would fight. We need better, sound reasons why Voss wouldn't just kill us himself and claim the credit for finding the weapon and we need more companion interaction that is full of flavor and tension and drama. Not to the point of being unfun, mind you, but some where it makes sense, like this scene.
