IN THE HOUSE OF THE TISROC 

question

1.Who came into the room Lasaraleen and Aravis were hiding in?  

Prince Rabadash, the Tisroc and the Vizier Ahosta. 

2.What were they discussing?  

 Prince Rabadash planned to carry off  Queen Susan, and pretended without  the Tisroc's agreement. He would take but two hundred horse and ride across the desert. And then ride through the pass above Anvard and down through Narnia to Cair Paravel, catch off Queen Susan and then ride back to Anvard. 

3.Why did the Tisroc, Prince Rabadash and the Grand Vizier meet in the old part of the palace? 

Because the Tisroc hoped that no living soul knew of this council they three held.