The episode title is part of the quote "Better to reign in Hell than serve in Heaven" from John Milton's epic poem "Paradise Lost", which Paracelsus quotes at the episode's climax.
The half-mask Paracelsus wears and the burn scars on his face are reminiscent of the mask and facial disfiguration of the Phantom from "The Phantom of the Opera".
Last episode of James Avery as the character Winslow.