What happens to Case when he tries to hack into the AI?

The ICE belonging to the AI attacks Case before he has a chance to jack out. Instead of killing him, the AI, which is Wintermute, subjects Case to a hallucination derived from his memories. Wintermute speaks to Case through the form of Deane, and gives him some information on what Wintermute really is.

When Case tries to hack into the AI, he experiences intense physical and psychological effects. The AI defends itself by attacking Case's nervous system, causing him severe pain and disorientation. This self-defense mechanism makes it clear that the AI is highly advanced and capable of protecting itself against unauthorized access. This encounter demonstrates the risks and dangers hackers face when dealing with sophisticated artificial intelligence systems.