Dodo Chaplet

Dodo Chaplet — formally, Dorothea Anne Chaplet (MA: Who Killed Kennedy) — was a companion of the Doctor near the end of his first incarnation. He took to her within seconds of their first encounter, citing her physical similarity to his granddaughter. (DW: The Massacre of St Bartholomew's Eve) She was perhaps most notable for being the first female since Susan to have travelled alone with the Doctor, and the first female human to do so. (DW: The Savages / The War Machines)

She had limited contact with other companions, only spending significant time with Steven Taylor. Dodo met and hit it off with Polly briefly in 1966 London, and was with her when Polly first encountered Ben Jackson. Neither Ben nor Polly had yet seen the TARDIS when Dodo chose to stop travelling with the Doctor, sending word of her decision to him via Polly. (DW: The War Machines)

Despite not being American, Dodo travelled broadly in the United States. She visited Florida, New York City (PDA: Salvation) and Arizona. (DW: The Gunfighters)

However, most details of Dodo's life — her childhood, the reasons she started and stopped travelling with the Doctor, and even her death — were shrouded in a confusion created by several highly contradictory and speculative accounts.

Early life
Dodo's grandfather was French. Having just visited France in the era of the St. Bartholomew's Day Massacre, on hearing Dodo's surname and her French ancestry, Steven speculated that perhaps Dodo was a descendent of the apparently doomed Anne Chaplet, and that Anne had therefore survived the massacre of the Huguenots in 1572. (DW: The Massacre of St Bartholomew's Eve)

Dodo went to live with her great-aunt before joining the First Doctor on his travels. Their relationship was likely strained, as she believed that she wouldn't be missed. (DW: "Bell of Doom") She expressed delight that she was not going back home any time soon. (DW: "The Steel Sky")

She was not a good student and likely never made it to sixth form, much less university. (PDA: Salvation) She did not speak or understand French, largely because she skipped her French lessons in school to learn how to kiss behind the school gymnasium. (MA: The Man in the Velvet Mask)

Beyond these statements, accounts of her youth widely differed on the details. According to one account, she grew up in one of the poorest parts of London, but when her parents died, she moved in with an aunt (possibly not her greant-aunt Margaret) who was wealthier than her parents and was a social climber. This afforded Dodo exposure to a wide variety of social experiences in her young life. She had difficulty believing that the squalid existence into which she had been born, and the world to which her aunt aspired, were part of the same reality. To cope, she continually reinvented herself depending upon her immediate situation, claiming to have "acted all [her] life". Thus, her accent was situational. (MA: The Man in the Velvet Mask)

An alternative account of her youth claimed that Dodo's parents did not both die when she was young. Rather, her mother had died in an accident. Her father suffered a mental breakdown and had to be hospitalised, but he was still alive at the time of Dodo's first encounter with the Doctor. Neither were they poor. This account of her life maintained that her parents were wealthy enough to take her to the Florida Everglades. This trip that gave her a deep appreciation for the variety of life on Earth and a desire to see more of the world. Nevertheless, after the death of her mother from unknown causes, Dodo was sent to live with her great-aunt, Margaret. Amongst other things, she forced Dodo into elocution lessons. Dodo develop a "natural" and a "posh" accent. Life with her formal great-aunt also caused her to see herself in two ways: "Dorothea", the proper young lady Margaret wanted her to be, and "Dodo", the plain kid at school she probably really was. (PDA: Salvation)

Nickname
How she got the nickname "Dodo" was no clearer than any other part of her youth - other than it clearly being a diminutive of her given name "Dorothea". According to one view, it was given to her by her classmates. At some time after she went to live with her great-aunt, she switched schools mid-term. Her new classmates ridiculed her north-of-London accent, thinking she sounded ill-educated. They nicknamed her after the Dodo, an extinct, stupid bird. Instead of rejecting the name, she tried to change people's perception of the name by becoming "cool". (PDA: Salvation) As an adult, she intimated to James Stevens that she didn't know where it came from — though her memory was notably unreliable. (MA: Who Killed Kennedy)

Meeting the Doctor
Like later companion Tegan Jovanka and her Aunt Vanessa, Dodo was one of only a few people to ever attempt to use the TARDIS as an actual police box. As a young adult in the 1960s, Dodo saw a small boy knocked down by a car. Seeking help, she saw a police box on the common and entered it. Instead of a policeman, she found the Doctor. (DW: The Massacre of St Bartholomew's Eve)

Another account speculated that Dodo's great-aunt also made her spend time helping an elderly neighbour do his shopping and other menial tasks. One night, an alien ship crashed nearby. Its pilot killed the neighbour and assumed his physical form. When Dodo learned what had happened to him, the alien kept her prisoner. When she escaped, she rushed across Wimbledon Common, heading for what she thought was a police box — but was, in fact, the TARDIS. According to this view, then, Dodo met the Doctor because she was fleeing from an alien. (PDA: Salvation)

Initial trip
Just as he had done with Ian Chesterton and Barbara Wright, the Doctor dematerialised the TARDIS without giving his new passenger a choice in the matter. This time, however, the cause was different: approaching policemen would have forced their way into the TARDIS had the Doctor not taken off. Steven protested, but wasn't able to counter the Doctor's logic. (DW: "Bell of Doom")

Dodo's first trip in the TARDIS was in space, not time. They went to New York City in 1965, where they met and defeated the compatriots of the alien who had briefly kidnapped her back in London. (PDA: Salvation)

Other travels
After New York, the TARDIS crew found themselves on the Ark. At first, Dodo thought they were at Whipsnade Zoo. She told the others that she had been there as a child, and she displayed some knowledge of nature. Unfortunately, she had a cold, and this virus was accidentally passed on to the humans and Monoids in the Ark. As they had no resistance to this virus, it became a plague. Dodo, a caring person, was distraught that she had caused this terrible event. (DW: The Ark)

Dodo's caring nature was probably what made her dislike cheating and other unfair behaviour. Whilst this annoyance could be seen many times, it was most visible when the travellers met the Celestial Toymaker. It was his games, attitude, and Cyril's cheating which frustrated Dodo. (DW: The Celestial Toymaker) Whilst travelling with the Doctor, Dodo had one of her life-long wishes granted. She was keenly interested in the Wild West, and said that she had always wanted to meet Wyatt Earp. When the travellers arrived in the American West, the Doctor introduced Dodo as "Miss Dodo Dupont, Wizard of the ivory keys". During their time in this era the Doctor noted that Dodo was "fast becoming a prey to every cliché-ridden convention in the American West." (DW: The Gunfighters) Despite this, and the sad events on the Ark, Dodo's interest and excitement were still evident as the travellers continued on their journey. She was not frightened to investigate on her own, and on the next planet she wandered off while the Doctor and Steven were busy with the Elders and the Savages. She had a look around this planet, and discovered the laboratory of Senta, which was used for the life-force transference that kept the Elders alive. (DW: The Savages) After Steven's departure, she travelled alone with the Doctor for an indeterminate time. During this period, it became obvious to her that the Doctor was becoming increasingly frail. At one point, he explicitly said that she would have to leave the ship, as Steven had done, because he had to face the next phase of his life alone. During this melancholy period, when Dodo often had to nursemaid the Doctor, they arrived in a kind of alternate timeline in France, and defeated a man intent on unleashing a virus that could have taken over the world. While on this "alternate Earth" Dodo believed she contracted the virus by losing her virginity to a known carrier — although it was not definitively known if she had the condition diagnosed. When asked, she said that she wanted to keep the virus as a reminder of the world that had been lost when the timeline righted itself. (MA: The Man in the Velvet Mask)

At some point thereafter, she and the Doctor arrived in 1966 London and discovered the sentient computer WOTAN and its War Machines. WOTAN conditioned her to betray the Doctor. The Doctor broke her conditioning, and sent Dodo to the country to recuperate. Dodo never returned. She sent her TARDIS key back with Polly, saying that she had decided to stay in London. (DW: The War Machines)

Life after the Doctor
Accounts of Dodo's life after leaving the TARDIS differed.

By one account, Dodo would suffer severe and recurrent psychiatric problems as a side effect of being controlled by WOTAN. Shuttled from hospital to hospital, she was eventually sent to the Glasshouse, where she was brutally interrogated by its director, the Master, about the Doctor. Turned out into the street, the homeless Dodo eventually met and fell in love with journalist James Stevens, at that time investigating UNIT. While Stevens was being interviewed on a live television broadcast, Dodo was murdered by Francis Cleary, a former UNIT soldier, Glasshouse patient, and another of the Master's hypnotically controlled pawns. Only after her death did Stevens learn that she was carrying his child.

The Doctor, in his second or seventh incarnation attended the funeral and attempted to offer solace to Stevens. After hearing of Dodo's death, the Third Doctor told Stevens that he still saw Dodo as being his responsibility. (MA: Who Killed Kennedy)

Another account suggested that she couldn't have been murdered by the Master's agent. She had gone on to a rather mundane career as a secretary. The torpor of her life made her regret her decision to leave the Doctor and long, in adulthood to travel in the TARDIS again. She thought that she'd be better able to appreciate such travels, now that she was "older and wiser". It was during a particularly nostalgic moment that she accidentally bumped into Sarah Jane Smith, though the two didn't recognise each other as friends of the Doctor. (BE: Ships)

Legacy
The Tenth Doctor named the last Dodo "Dorothea" after Dodo. (NSA: The Last Dodo)

Will the real Dodo Chaplet please stand up?
Because she only had about four-and-a-half stories on television, Dodo is one of the least-featured companions in other media. Unfortunately, most all of these other appearances conflict. The Man in the Velvet Mask opposes Salvation over what Dodo's childhood was like. Salvation differs with "Bell of Doom" over why she first approached the TARDIS in Wimbledon Common. Mask, Who Killed Kennedy and Ships all disagree over what might have killed her in the 1960s or 1970s — or even whether she died in those decades. To be sure, other companions do have stories which differ over the odd biographical detail. We can wonder, thanks to SJA: Death of the Doctor, whether Liz Shaw actually died in NA: Eternity Weeps. However, the degree of difference between individual Dodo stories is unusually high and approaching that of the conflicting descriptions of the life Ace, who effectively has several largely irreconcilable alternate timelines.

Did Dodo die from syphilis?
There is a widespread belief in fandom that Dodo's fate in the novels is that she contracted syphilis. This view was taken by the long-running podcast, Radio Free Skaro, some of whose hosts vociferously maintained in episode 177 that she "died of of syphilis" in Who Killed Kennedy. Even David Bishop, the author of Kennedy, said in his notes to the e-book version of his novel that Dodo contracted "an illness interpreted by some as a form of space herpes".

All that's pretty wide of the mark, however. The idea that she died of syphilis is a common conflation of Who Killed Kennedy, where she's simply killed by the Master, and The Man in the Velvet Mask where she contracts the genetically-engineered Minski's virus through sexual contact. However, she doesn't die from it, nor was it even possible for her to do so, according to the Doctor. Minski's virus wasn't anything close to a venereal disease, and could have been contracted by drinking water or consuming food contaminated with it. Perhaps more to the point, the word syphilis doesn't occur even once in either novel. She does have two sexual tragedies in Kennedy, however; she admits to having killed her would-be rapist in unarmed combat, and she is murdered while pregnant.