There's a locked door in Nathan's new apartment. At night, it opens.
He doesn't care - until he starts hearing eerie scratching noises coming from behind it. Footsteps resound in his apartment, objects are mysteriously moved out of place, and no matter what he tries, he can't get the door open. Then one night, the door opens on its own, revealing a long, dark corridor. Nathan is immediately compelled to explore it, going further inside each night, ignoring the distant creaking sounds.