Following Iblis's hint, Harry and Ron found the slip of paper in Hermione's tightly clenched hand bearing the record about the Basilisk. After a brainstorming session, they basically sorted out their thoughts. The monster in the Chamber of Secrets was indeed a Basilisk, which explained why only Harry could hear its voice.
Moaning Myrtle in the bathroom was the student who died fifty years ago from looking directly into the Basilisk's eyes, and the entrance to the Chamber was located right inside the girls' bathroom she haunted. The reason Hermione and the others hadn't died instantly was because they had seen the Basilisk's eyes indirectly through other reflective objects.
Hearing Professor McGonagall make an emergency announcement calling for all professors, they trailed along and discovered the newly appeared bloody message. From the conversation, they learned that Ginny had been taken into the Chamber. Lockhart, who had been boasting days earlier about knowing the location of the Chamber, had been assigned the task of dealing with the monster alone by McGonagall and Snape.
Chapter 62