This is the passage Sam Neill reads as the walls of the world tear open, and he watches Elder Horrors rush toward reality. I mostly put this here so I won't lose it.
In The Mouth of Madness
“Trent stood at the edge of the rip; stared into the illimitable gulf of the unknown, the Stygian world yawning blackly beyond. Trent's eyes refused to close. He did not shriek, but the hideous unholy abominations shrieked for him, as in the same second he saw them spill and tumble upward out of an enormous carrion black pit choked with the gleaming white bones of countless unhallowed centuries. He began to back away from the rip as the army of unspeakable figures, twilit by the glow from the bottomless pit, came pouring at him toward our world.”