"Torchwood" is an anagram of "Doctor Who". When the first series of Doctor Who (UK) was being made, television pirates were desperate to acquire the preview tapes. One of the people in the office had the idea of labeling the tapes with the anagram "Torchwood" rather than "Doctor Who", as a security measure to disguise the tapes when they were delivered from Cardiff to London. Writer Russell T. Davies liked this idea so much that it later inspired him to use it as a title when creating this spin-off series.
"Torchwood" is the first Doctor Who spin-off to make it to series, and the first dramatic spin-off of Doctor Who (UK). A failed attempt to spin-off a series from the original Doctor Who (UK) (1963) resulted in the television special, K-9 and Company: A Girl's Best Friend (1981) (TV), featuring the characters K9 and Sarah Jane Smith. After failing to produce a series, the pilot was broadcast as a seasonal special.
Two of the regular characters - Jack Harkness, and Toshiko Sato - originally appeared on the parent series, Doctor Who (UK). Toshiko (Naoko Mori) was the government forensic pathologist called in to perform the autopsy on the alien corpse in "Doctor Who" (2005) {Aliens of London (#1.4)}. Jack (John Barrowman) first appeared in "Doctor Who" (2005) {The Empty Child (#1.9)} and became one of the Doctor's companions. He was last seen in "Doctor Who" (2005) {Journey's End (#4.13)}. Eve Myles played a similarly named character on the parent series in the episode, "Doctor Who" (2005) {The Unquiet Dead (#1.3)}. It was heavily suggested that the two are related in "Doctor Who" (2005) {The Stolen Earth (#4.12)} when the Doctor and Rose Tyler mention that she resembles the earlier character and she confirms that her family has lived in Cardiff since the 1800s. Freema Agyeman was a series regular in series three of Doctor Who (UK), as the Doctor's companion 'Martha Jones'. Agyeman later appeared in "Torchwood" (2006) {Reset (#2.6)} and the two following episodes as the same character. Peter Capaldi plays 'John Frobisher' in the Children of Earth specials, and also played 'Caecillius' in "Doctor Who" (2005) {The Fires of Pompeii (#4.2)}. Also in Children of Earth, _"Torchwood" (2006) {Children of Earth: Day Four (#3.4)}_ Nicholas Briggs plays Rick Yates. Nicholas is the voice of the Daleks and the Cybermen in Doctor Who (UK)
In certain episodes, Torchwood members use a drug called "Retcon" to wipe the memories of people who know too much about the organization. Retcon is a term derived from "Retroactive Continuity" and is used in serialized fiction, especially comic books, for when new events effectively change or erase the established history of a series.
Torchwood was the subject of a background arc during the 2006 series of Doctor Who (UK), with most episodes containing at least one reference to the Torchwood Institute, beginning with the 2005 series episode "Bad Wolf" and culminating in the Institute's appearance in "Army of Ghosts" and "Doomsday". The 2006 episode "Tooth and Claw" details the origins of Torchwood. After "Torchwood"'s debut, it was referenced again in the Doctor Who Christmas special, "The Runaway Bride".
Prior to becoming involved in the revival of Doctor Who (UK), Russell T. Davies had conceived of this series as a concept about an alien-fighting team called "Excalibur". After DW became a success, Davies decided to rework the idea as a spin-off, and he latched on to the codeword "Torchwood" for the core organisation.
Owen is the only member of the Torchwood team never to have had direct contact with the Doctor. Jack has been companion to both the Ninth and Tenth incarnations; Toshiko met the Ninth Doctor while examining the space pig in "Doctor Who" (2005) {Aliens of London (#1.4)}; and Gwen and Ianto met the Tenth Doctor through the sub-wave network in "Doctor Who" (2005) {The Stolen Earth (#4.12)}.
In several episodes throughout series 1, posters bearing the slogan "Vote Saxon" are visible in several shots, most noticeable in episode 12 ("Torchwood" (2006) {Captain Jack Harkness (#1.12)}) on the door of the dance hall. In series 3 of Doctor Who (UK), which was broadcasting during the same year, "Saxon" was the running keyword arc and the identity of "Mr Saxon" was the subject of the season finale.
Jack's primary gun for the series is a Webley Mk VI .455 revolver. The Webley was the standard issue sidearm for the British military from 1887 to 1963. In actuality, Jack's weapon is a Webley Mk IV .38. This is evident in the muzzle diameter and overall frame size of the gun. The Mk VI variant, introduced in 1915, is probably the most best-known model. The Mk IV variant rose to prominence from 1899-1902 and is still in use as a police service weapon in many countries.
John Barrowman (Captain Jack Harkness) and Eve Myles (Gwen Cooper) are the only actors to appear in every episode.
John Barrowman (Captain Jack Harkness), Eve Myles (Gwen Cooper), Kai Owen (Rhys Williams) and Tom Price (PC Andy Davidson) are the only actors to appear in all four seasons.
[SPOILER] Jack Harkness vows he'll never do pregnancy again. In "Doctor Who" (2005) {Last of the Time Lords (#3.13)}, Jack reveals his nickname was "The Face of Boe" due to being the first Time Agent recruited from the Boeshane Peninsula, and in "Doctor Who" (2005) {The Long Game (#1.7)}, a news report announces that The Face of Boe is pregnant, with the caption "Baby Boemina", suggesting he doesn't keep that vow.
The hand that Captain Jack Harkness is so fond of and keeps safe belongs to Doctor Who. The Doctor had his hand cut off during the climatic sword fight with the Sycorax Leader in "The Christmas Invasion" ("Doctor Who", Season 2, Episode 0) but he was able to regenerate his hand and defeat the leader.
If one watches carefully during the scene when Jack and Gwen investigate the alley beside the nightclub, a pair of bare human feet can briefly be seen poking out of a trash can behind Jack's shoulder.
Just before filming the first chase scene, which was filmed over several nights, John Barrowman sprained his ankle, forcing a quick rewrite which put Jack at the wheel of a car attempting to head off the suspect.
The food that Jasmine is setting out to hand around at the party is Fairy Cakes.
The W.B. Yeats poem The Stolen Child is used by the fairies to summon Jasmine "Come away oh human child to the waters and the wild. With a fairy hand in hand for the world's more full of weeping than you can understand".
Jack Harkness compares the fairies to Mara, a specter or wraith-like creature in Germanic and particularly Scandinavian folklore, thought to cause nightmares, also called "spirit of confusion". Doctor Who (UK) (1963), with which Torchwood (UK) shares continuity via Doctor Who (UK), also had a creature called a Mara ("Doctor Who" (1963) {Kinda: Part One (#19.9)} to "Doctor Who" (1963) {Kinda: Part Four (#19.12)}, "Doctor Who" (1963) {Snakedance: Part One (#20.5)} to "Doctor Who" (1963) {Snakedance: Part Four (#20.8)}, and Doctor Who: Time Crash (2007) (TV)), but it was based on the Buddhist demon of the same name and as such is unrelated.
This is the first time we see Owen use his skills from his previous career as a medical doctor.
The cast believed the building they were staying at during filming was haunted. At one point Eve Myles went to ask John Barrowman if she could share his room for the night, to find him wearing freshly-ironed Transformers pajamas when he answered the door.
The amnesia pill is called "Retcon". This term is also short for "retroactive continuity", which is the practice of deliberately changing previously established facts in a work of serial fiction.
While filming the scene in which Jack first tries the Resurrection Glove on one of the murder victims, John Barrowman accidentally said "maximum erection time", bringing production to a standstill until everyone recovered.
The 1950s passenger plane is a De Havilland DH-89A Dragon Rapide 6 with registration number G-AIDL
When Jack and Tosh leave at the end, the other Captain salutes. The salute he displays is a Royal Navy (or American) one, with the palm of the hand facing downwards; the RAF and Army salute with the palm facing forwards.
As Jack and Tosh are heading down the stairs in the club, the words "Bad Wolf" (the series 1 arc keyword for Doctor Who (UK)) can be seen in the graffiti on the wall at the top of the stairs.
On the door of the dance hall, there's a campaign poster for Saxon. This is the first official appearance of the "Mr Saxon" arc keyword for series 3 of Doctor Who (UK); except for a brief glimpse in a preview trailer, the keyword had not been seen in "Doctor Who" prior to this episode.
The name of the time-traveler, Bilis, is an anagram of "iblis", the primary name of the devil in Islam.
The name "Abaddon" was first mentioned in the Doctor Who two-part episode "The Impossible Planet/The Satan Pit" as one of the names for the Devil.