Nicole decided to go into Lyoko and try to stop Xana. Jeremy didn't want to send Nicole in to see Xana but he had no choice. If he did Nicole could be killed and on the other hand if he didn't she would be able to live. Nicole just got madder and madder when Jeremy didn't send Nicole into Lyoko. So he sent Nicole and Odd into Lyoko to meet Aelita so they could stop Xana.
Once they got to the activated tower they had to go through many rooms to get to Xana. The room before they met Xana was hard to get through. Odd lost about 75% of his life points and had only 25% left. He sent Nicole and Aelita to fight Xana. What they got was a big surprised.