"It's not paranoid if they're really out to get you."
That statement certainly applied to Claire Bennet. After Matt Parkman and Ted Sprague came to her house, she had lived knowing that people were after her. And even though she chafed under the restrictions her father and grandmother placed on her, she was afraid. She had nightmares. Some nights it was the Company, some nights it was Sylar.
That was the reason for the switchblade. She had picked it up in New York. She didn't carry it with her – it rarely left her room. But every night, she made sure that it was nearby – under her pillow, in the dresser drawer, even in her hand. It was her way of being safe. It was her way of protecting herself.
Until her nightmare came true.
It was exactly that – her worst nightmare come to life. Claire was trapped in her house with a telekinetic serial killer who wanted her ability. He caught her. He cut open her skull. He took her ability.
And she lived.
After that, Claire thought that she would never be able to be afraid again. She had survived her worst nightmare. And though her life wasn't exactly stable, Claire knew that she would survive. She had no reason to be afraid. And she no longer slept with a switchblade under her pillow.
Then Gretchen was attacked by Becky. And Claire was afraid again.
They got out alive, thankfully. But that night, as they went to bed, Claire took the switchblade from her bag, and placed it under her pillow.
She wasn't afraid for herself.
She was afraid for Gretchen.
It wasn't as if Claire had nothing to lose before now. She had her family. But Dad could take care of Mom, and Lyle, and Mr. Muggles, and himself. But Gretchen was different. She was Claire's responsibility. Claire wasn't sure why she felt that way about Gretchen. But she did.
Which is why a girl who can't get hurt sleeps with a switchblade under her pillow.