In the Room of Requirement, Will was pulling the Diary out from beneath the Book Trunk.
Professor McGonagall had refused to give him permission, so Will considered getting special authorization directly from Dumbledore.
But he couldn't waste tonight. Will opened the Diary and wrote, "Who are you, and why did you ask about my cousin? If you won't tell me, I'll hand you over to the headmaster. Our headmaster is Dumbledore, the greatest wizard in the world."
Will meant to bluff the Diary again, hoping to clear up his questions about the Chamber of Secrets.
The moment the Diary received news of Dumbledore, it reacted as if struck by a nerve:
"I'm Tom..."
Will had dealt with the Diary long enough to know how to handle it. He quickly invented a new identity: Ivan Selwyn's cousin, Daniel Drakecliffe, a second-year Slytherin.
Will spent half the night chatting "enthusiastically" with the Diary, letting hints of his hunger for power slip into his writing as though by accident.
In truth, Will thought that if the Diary couldn't tell him anything about the Chamber of Secrets, he would hand it over to Dumbledore and get something in return.
Tom, meanwhile, was plotting how to gather enough magic to control Will's body. He had no idea what Will was thinking.
The next day, Will went to Dumbledore and secured special permission to enter the Restricted Section almost at will. He could borrow no more than three books at a time, and Madam Pince would record each title on the authorization slip.
The information on the slip would be sent back to Dumbledore. It was an electronic record system in all but name.
Dumbledore explained that some things were not suitable for Will to read yet. Certain advanced Dark Magic could influence even adult wizards.