Canton Everett Delaware III

Canton Everett Delaware III was an ex-FBI agent who accompanied the Eleventh Doctor during the latter's visit to the United States of America in 1969, having been kicked out of the Bureau for wanting to have a gay marriage. He served as the Doctor's fourth companion (as he already had Rory, River and Amy) during his investigation of the Silence. He quickly came to respect the Doctor during their quest to defeat the Silence, hoping to have another adventure with him in the future.

The Silence
Canton was an FBI agent who was forced to quit the Bureau. Six weeks after his resignation, on 8 April 1969, he met with President Nixon at the White House to investigate mysterious telephone calls Nixon was receiving. In the Oval Office, Canton met the Eleventh Doctor and allowed him to help in the investigation. Canton travelled with the Doctor to Florida in search of the little girl who had been calling. Rory Williams explained to Canton how the TARDIS travelled through both time and space and was bigger on the inside. (TV: The Impossible Astronaut) The Silence arranged for the companions to be declared fugitives and the Doctor held prisoner in Area 51. Canton pretended to lead the hunt for Amy, Rory and River to prevent the Silence from realising their presence was known. After the Doctor was sealed in a dwarf star alloy prison that prevented anything getting out, he and Canton revived the captured Amy and Rory, recovered River Song and departed in the TARDIS - which had been hidden in its invisible form behind the Doctor as the prison was constructed - to track down the little girl.

After Canton shot one of the Silence, he used Amy's video phone to record the Silence saying, "You should kill us all on sight!". The Doctor arranged for that message to be broadcast during Neil Armstrong's moon landing; the Silence essentially ordered every human who ever saw the footage to murder them and forget they'd done it. As the Doctor departed, he suggested that Nixon allow Canton to get married, but the understanding that Canton intended to marry a black man prompted Nixon to reconsider the idea. (TV: Day of the Moon)

Meeting again
In 2011, Canton was invited by a future version of the Doctor to the place where the Doctor would be shot and killed. There he met River, Amy and Rory again, told them that it was definitely the Doctor and that he was really dead. He left them gasoline to burn the Doctor's corpse. The Doctor had secretly used a Teselecta duplicate to fake his own death, and the gasoline barely singed it. (TV: The Impossible Astronaut, The Wedding of River Song) Canton also told them that he wouldn't see them again, but they would see him. This was before they were going to meet his younger self later in their personal timelines. (TV: The Impossible Astronaut)

Personality
As a former member of the FBI, Canton was used to using violence in order to accompish a goal, shooting a Silent twice at point blank range. Although he got a doctor to tend to the Silent's wounds later, this was only so that he could lull it into a false sense of security until it said that humans should kill its species on sight. Canton also casually stated that if the Doctor did not do a satisfactory job of solving the mystery of Melody Pond he would shoot him, although this was before he became the Doctor's friend. He was a skilled actor, being able to fool the Silence into thinking that he was hunting the Doctor's companions when in reality it was all part of the Doctor's plans to overthrow the Silence. The fact that the Silence were most likely watching him most of the time, due to the fact that nobody would realise that they were even there, is further evidence of Canton's impressive acting abilities.

Canton often displayed a dry wit, such as when he said "welcome to America" after shooting one of the Silence. (TV: Day of the Moon) He was usually very calm and level headed, showing no signs of panic when confronted with the Silence, and although he seemed impressed by the TARDIS he did not get overexcited about it, merely commenting that he liked the Doctor's "wheels". Canton was able to quickly adapt to unfamiliar situations, presumably because of his FBI training, and was able to accept the existence of aliens and time travel very easily. (TV: The Impossible Astronaut)

Canton was homosexual, and wanted to marry a black man. (TV: Day of the Moon) He was also a loyal friend and the Doctor trusted him enough to invite him to his funeral at Lake Silencio. Given that he knew the Doctor was definitly "dead" and claimed that it was definitly him, the Doctor may have trusted him with the truth about his "death." (TV: The Impossible Astronaut, The Wedding of River Song)

Behind the scenes

 * Mark Sheppard, who played Canton in 1969, is the real-life son of William Morgan Sheppard, who played him in 2011, and suggested his father for the role. Both actors appear in the Star Trek franchise as well as in the Nintendo Wii FPS The Conduit.
 * Mark Sheppard has stated he would like to return as Canton and added he sees Canton "more like the Brigadier than Amy or Rory"