  The 2010 episode of \emph{Futurama} titled \emph{The Prisoner of Benda}
centers around a machine that swaps the brains of any two people who use it.
The problem is, once two people use the machine to swap brains with each other,
they cannot swap back.
  In this article, we present a new proof of this theorem and also a
generalization of it to what would happen if, instead, the machine swapped
cyclically the brains of $p$ characters, where $p$ is prime.
