i did what the oricals said but i dont know what the object that i need is. any thoughts. thanx

I assume you are talking about the three oracles behind the wall of flame? You need to have the person who's talking be in possession of the maven signet (ring) that you got at the end of the crypt. It identifies you as the "Chosen One" and the middle oracle will open the tunnel for you.

My problem is I can't talk to her. "Speak to my Sister..."

I've tried talking to all three. (This is of course after she said I
was the chosen one)