John Cavil (Number One) is a fictional character and the main antagonist from the re-imagined Battlestar Galactica television series.
John Cavil, aka Number One, is a humanoid Cylon model that appears as a highly rational, eccentric man in his late-sixties.
As revealed on Battlestar Galactica: The Plan, the Cavil that was stationed in Caprica learned from Samuel Anders the motives for the resistance; that humans do not leave anyone behind, even their dead.
Cavil is insistent the Cylons not seek out or discuss the Final Five models and tries to prevent D'Anna from learning their identities, even threatening her at gunpoint in "Rapture".
His first appearance is as a religious counselor provided by the fleet, with whom Chief Tyrol meets after he physically attacks deck hand Cally Henderson when she awakens him from a recurring nightmare.
A second version of Cavil appears among the survivors from Caprica after Kara "Starbuck" Thrace leads a rescue mission to the planet.
Adama and Roslin furiously reject the idea, stating they simply cannot walk away after the Cylons have destroyed their home worlds.
Despite the apparent sincerity of the message, and the offer of truce, Roslin orders both Cavils to be airlocked, suggesting they will rapidly discover whether or not God exists.
One Cavil in particular takes pleasure in blackmailing Ellen Tigh for sexual favors in exchange for releasing her husband Saul from captivity and not killing him.
Later in the season, Cavil is one of three Cylons to board Galactica to meet with William Adama and Laura Roslin about the Eye of Jupiter artifact.
Upon returning to his Basestar, Cavil feels that the annihilation of Galactica is the best option, given the standoff, because Cylons are machines, and can wait out the human fleet.
In "Rapture, Cavil finds D'Anna in the temple on the Algae Planet, and, realizing she has come to discover the identities of the Final Five, he orders her at gunpoint not to proceed any further.
He claims he and the other Cylon models agree the Number Threes must all be "boxed" – deactivated, with their memories placed into cold storage.
In "Six of One," Natalie, the leader of the opposing faction, demands he stop lobotomizing the Raiders, and reveals that she has restored free will to the Centurions.
Cavil hopes she will be able to mediate peace between the warring Cylon factions, but she kills him and escapes with Helo and a Number Eight.
In "No Exit", it is revealed Ellen Tigh was involved in the creation of Cavil, modelling him after the image of her own father, John.
[5]After Ellen Tigh is poisoned by her husband, she resurrects aboard one of Cavil's ships and is held prisoner there for 18 months (No Exit).
It is later revealed, however, Ellen's escape was orchestrated by Cavil to sneak Boomer onto Galactica in order to kidnap Hera Agathon.
"[3] Cavil wants Hera, as he sees her as the only chance for the Cylon race to continue, following the destruction of Resurrection.
After Boomer helps Hera escape, Cavil personally leads a boarding party onto Galactica to retrieve her.
As the Final Five come together to generate the data necessary for Resurrection technology, Tyrol, discovering Tory was responsible for the death of his wife Cally, breaks the link and kills her.
In Battlestar Galactica: The Plan, the history of the Cavils found in the fleet and on Caprica during "Lay Down Your Burdens" is expanded upon.
The fleet version of Cavil is revealed to have been with Ellen Tigh when the attack on the Colonies commenced, having wanted to see just how much suffering she had undergone and what she had learned about the evils of humanity.
During this time, he reluctantly befriends a young orphan named John, but murders the boy after he explicitly calls them friends.
However, he intends to box the other Cavil, effectively putting him into cold storage to prevent him from spreading his heretical ideas to the rest of the Cylons.
According to Jon D. Bohland, Cavil has been described as the Cylon who best "fits the cinematic genocide perpetrator profile as the stereotypical remorseless killer with a lust for power and violence".
[7] While an atheist himself, even described as the Cylon who "exhibits the most resistance to religion", Cavil, in one of his forms masquerading as a human priest, is able to use it to manipulate those who are more religious, convincing them that they are acting as part of God's will.
[7][8][9] Bohland, as well Patrick Thaddeus Jackson remarked that Cavil's mentality is warped by his loathing of his creators, a form of an Oedipal complex.