Piter De Vries is a fictional character from the Dune universe created by Frank Herbert. He is featured in Dune, the original novel in the science fiction series, as well as the Prelude to Dune prequel series by Brian Herbert and Kevin J. Anderson.
De Vries was a Mentat in the service of Baron Vladimir Harkonnen. This Mentat was a particular favorite of the Baron because the Tleilaxu had shown him to be an amoral sadist, making him an ideal candidate for the Baron's torturer.
In David Lynch's 1984 adaptation of the first novel, De Vries was played by Brad Dourif. He was portrayed by Jan Unger in the 2000 Sci Fi Channel Dune miniseries.
De Vries' loyalty to his master was unusual in that he continued to serve the Baron with great enthusiasm, even though his Mentat abilities and great intelligence confirmed his suspicions that his master planned to eventually kill him. As he says in Dune
But you see, Baron, I know as a Mentat when you will send the executioner. You will hold back just so long as I am useful. To move sooner would be wasteful and I'm yet of much use.
, it is established that De Vries pioneered a type of toxin called "residual poison
", which remained in the body for years and required an antidote to be administered regularly. One such fatal poison was used by the Harkonnens on Thufir Hawat
(the House Atreides Mentat), in order to keep the Mentat's allegiance as the only provider of the antidote (in the 1984 movie version, it is shown that Hawat has to milk a gruesome captive cat for the antidote every day). The poison was in fact administered without Hawat's knowledge as a way to kill him (an otherwise daunting task, as Hawat was a master assassin) should the need arise. Hawat's "loyalty" came from his desire to wreak his vengeance on the Imperium.
De Vries is generally regarded as architect of the plan to destroy the Harkonnen's long-time enemy, House Atreides, while returning the Baron's stewardship over Arrakis. He died on Arrakis shortly after House Harkonnen's troops and Imperial Sardaukar had captured Duke Leto Atreides. Leto had been given a false tooth containing a poisonous gas by Wellington Yueh, the Suk doctor who betrayed House Atreides. When the tooth was crushed, the intended victim—the Baron Harkonnen—escaped but De Vries was not so lucky.
Prelude to Dune
In Dune: House Corrino
, it is revealed that the Reverend Mother Gaius Helen Mohiam
secretly killed the original Piter De Vries after the Mentat discovered the Harkonnen heritage of Lady Jessica
and her newly born son Paul
and attempted to kidnap and ransom the infant. Mohiam effectively preserved this secret by murdering De Vries and arranging for his corpse to be shipped home to Giedi Prime
. An enraged Baron was left with no choice but to order a duplicate from the Bene Tleilax, who would become the Mentat De Vries featured in Herbert's original novel Dune