Angier's theft of Borden's teleportation illusion in the film echoes many real-world examples of stolen tricks among magicians. Outside the film, similar rivalries include magicians John Nevil Maskelyne and Harry Kellar's dispute over a levitation illusion. Gary Westfahl of "Locus Online" also notes a "new proclivity for mayhem" in the film over the novel, citing the murder/suicide disposition of Angier's duplicates and intensified violent acts of revenge and counter-revenge. This "relates to a more general alteration in the events and tone of the film" rather than significantly changing the underlying themes.