Mr. Coal's mansion hosts eight guests for a mysterious dinner. The butler welcomes them and seats them at the table. For a brief moment, there is a power outage, plunging everything into darkness. During the blackout, a gunshot is heard, along with screams and other indecipherable noises. The butler grabs a flashlight and goes to the electrical panel, but when the lights come back on, the host's body is lying on the carpet in the hall.

Who is to blame?