The Hassassin (referring to the Medieval Haschaschin of Hassan Ibn Sabbah; frequently referred to as "The Killer"), also known as "Mr. Grey". is the secondary antagonist of the 2000 Dan Brown novel Angels and Demons and the 2009 film adaption of the same name. The Hassassin is not part of the ancient Illuminati group. He is co-opted into carrying out evil deeds under the Illuminati name by a character called "Janus". He is of Arab descent and a Muslim man, numerous times referring to the crimes the Crusaders committed against his people.
He was portrayed by Nikolaj Lie Kaas.
In the prologue of the book, The Hassassin demanded a password from Leonardo Vetra to gain access into the Vetra's secret underground laboratory which contained a small, but nonetheless destructive, quantity of antimatter. When Leonardo failed to comply and give out the key, the Hassassin cut out one of Leonardo's eyes (which turned out to be the key into Vetra's underground laboratory) and branded the Illuminati logo onto his body. Leonardo's body was severely mutilated and his neck was twisted 180 degrees with one eye missing. The Hassassin stole antimatter (a very reactive and explosive substance when exposed with matter), in order to initiate revenge against the Roman Catholic Church in the Vatican City by the secret society organization The Illuminati.
After killing Leonardo, the Hassassin went to a prostitution house as a reward for himself, and has sex with a prostitute in bondage, whom he then briefly considers to murder for his pleasure. The Hassassin later kidnapped four Cardinals and made contact with Camerlengo Carlo Ventresca, Vittoria Vetra and Robert Langdon were discussing the missing antimatter from CERN. He gave information regarding the missing Cardinals and gave them warning "Every hour from 8pm each Cardinal will be branded with the four elements Earth, Air, Fire and Water in four different churches across Rome". After giving the warning he contacted 2 BBC News correspondents who were in the Vatican covering the papal conclave and gave the same information to them about the four missing Cardinals. In the movie, the Hassassin is played by Nikolaj Lie Kaas.
He branded the Earth symbol onto one of four Cardinals and murdered him through oxygen deprivation because of the Hassassin lodging dirt into the Cardinal's throat. The Cardinal was murdered at the first altar of science which was Chigi Chapel at the Santa Maria del Popolo. The second Cardinal was branded with the Air symbol and had his lungs punctured and asphysiated. Still alive, the cardinal (in the disguise of a tramp) was escorted to the second altar of science and left to die as Langdon and Vittoria arrived to the altar at the West Ponente of Saint Peter's Square. This death was seen in public and caused a frenzy with media networks beginning coverage about the death and possible speculations of other kidnappings.
The third Cardinal was branded with the Fire symbol and was burned alive at the third altar of science which was the Ecstasy of St Theresa at the church of Santa Maria della Vittoria. Unlike the other Cardinals, the Hassassin decided to leave this Cardinal alive in order for him to witness his own death. Langdon, Vittoria and Olivetti intercepted the situation at the church but failed to save the cardinal; after finding Olivetti's body in a manner similar to her own father's death, Vittoria is subdued and kidnapped by the Hassassin, after forcing Robert was to hide inside a sarcophagus, where he just escaped death by asphyxiation.
The Hassassin takes Vittoria to the Church Of Illumination, which he is using as his base of operations, and leaves her bound and gagged before he leaves with the fourth and final Cardinal. He confronts Langdon at a fountain, where he drowns the Cardinal and battles Langdon. He thinks Langdon is dead after their confrontation (unknown to him that he used an underwater air hose to stay alive) and returns to the church, greatly anticipating what he is intending to do to Vittoria.
As the Hassassin undresses to rape Vittoria, Langdon manages to find the church and confronts him with a large, metal pole. Langdon, however, is no match for the highly trained killer and forced out onto a balcony. As the Hassassin moves to finish Langdon, the yoga-trained Vittoria, who manages to escape her bonds by nearly dislocating her shoulders, attacks the Hassassin with a torch, burning his back and drawing his attention away from Langdon. With the Hassassin distracted, Langdon and Vittoria manage to push him over the side of the balcony, sending him plunging onto a pile of cannonballs below, breaking his spinal cord.
In the film adaptation, the Hassassin, now renamed Assassin, is portrayed as an assassin with an unknown nationality and motivation, other from monetary gain. His history is not mentioned, apart from a brief moment where he, in pain from a bullet wound, states "[the Church] made me a sinner". He retains a skill with weapons that suggests he has had military training. Unlike the sadistic and misogynic alter ego of the book, the movie character retains a few scruples, not kidnapping Vittoria and showing reluctance to drown the fourth cardinal at Bernini's Fountain of the Four Rivers, which fails as Langdon and a number of bystanders manage to save him just in time.
The Assassin chooses not to kill Langdon and Vittoria at the Church of Illumination, claiming he'd be "wasting bullets, since I wasn't paid to finish the both of you off". Instead of being killed by Langdon, the Assassin is killed when he climbs into a getaway car set up for him by the Illuminati master, with the pay-off for his work inside and attempts to drive off. The Assassin is double-crossed as there is a bomb in the car, which goes off when he turns on the ignition.
- His name comes from the medieval Middle Eastern name of Hassassins which was the root of the word "Assassins".