This art from freakyfauna.com made me think of Macbeth… throwing in a quote for fun:

 [Knocking within]

Macbeth:
Whence is that knocking?
How is’t with me, when every noise appalls me?
What hands are here? Hah! They pluck out mine eyes.
Will all great Neptune’s ocean wash this blood
Clean from my hand? No; this my hand will rather
The multitudinous seas incarnadine,
Making the green one red.