Just as he expected, once the door was open Gretel shot through it without a single shred of hesitation or forethought. The force of her own momentum threw her against the hallway wall opposite her door, fortunately for Sam, with her head turned away from him.
If it'd been the other way, she would've seen him and attacked, but all those crazed eyes saw was an open space, driven by pure compulsion. With a beastial snarl, leaving blood smeared on the wall in her wake, she started down the empty hallway.