Originally Posted by plyndrty

From what I understand, the suit case holds the soul of the big boss Marsellus Wallace. He made a deal with the devil to become the head crime boss. Then he crossed the devil and sent people after the suit case.

During the scene when Marsellus Wallace is talking to Bruce Willis (Butch) in the restaurant you see the band-aid on the back of his neck (Marsellus Wallace). That covered the hole where the devil removed his soul...