The Mercy Seat T-Shirt is in part inspired by Nick Cave's 1988 song from the album Tender Prey, and by the story of William Francis Kemmler, the first man to be executed in the electric chair in 1890.
The Mercy Seat song tells the story of a man about to be executed by the electric chair. The "Mercy Seat" refers both to the throne of God in the heavens, which the man feels he will soon visit, and to the electric chair.
Kemmler was sentenced to death for the murder of his common law wife and was the first man in the world to be sent to the electric chair. Contemporary witness reports describe a horrific scene where Kemmler survived the first shock and had to be shocked again, the entire process lasting over 8 minutes.