J is for... Jones, Martha

Travelling companion of the Tenth Doctor, and later a member of UNIT.

Martha was training to be a doctor at the Royal Hope Hospital in London when the building was hijacked by Judoon and transported to the Moon. Martha had been surprised to see the Doctor amongst the patients, as she had just bumped into him in the street earlier that morning on her way into work. He was impressed by the way she reacted to what had happened, keeping her cool whilst most staff and patients panicked. At one point, in order to decoy the Judoon, the Doctor kissed Martha - providing a transfer of genetic material - but she read more into this. Once the hospital had been returned to its proper location, Martha went to her brother Leo's birthday party at a local bar, but encountered the Doctor outside. He offered her a trip in the TARDIS, by way of a thank you for helping him earlier. To prove it was a time machine, he travelled back to that morning, which is when she had met him in the street.

Their trip took them to Elizabethan London, where Martha had the chance to meet Shakespeare and see one of his plays at the Globe. Martha used a bit of Harry Potter to help banish the witch-like Carrionites from the theatre. The Doctor extended his offer of a trip to the future as well as one to the past, and he took her to New Earth, and the city of New New York. Martha had a crush on the Doctor, and was not best pleased to discover that he was taking her to the same place he had taken Rose Tyler. She had wanted to see his home planet. After she was abducted by a couple of motorists on the city's interminable motorway, the Doctor eventually had to be honest with her and tell her about the events of the Time War. She then got to meet the Daleks in person, in 1930's New York. The Doctor then took her home, but he was intrigued by her sister Tish's new boss. Professor Lazarus claimed he was going to change what it meant to be human. This turned out to be rejuvenating technology, but something went wrong and he mutated into a monster.

The Doctor decided to offer Martha one more journey, but she refused. Either she travelled full-time, or not at all. The Doctor accepted this. However, Martha almost came to regret this as she realised, when trapped on a seemingly doomed spaceship, that her family would never know what happened to her.

Under threat from some formless aliens out to steal his body, the Doctor at one point had to disguise himself as a human school teacher, in 1913 England. Martha retained her memories, and posed as a servant in order to look after him. She was upset to see the Doctor fall in love with a human - that wasn't her.

Martha got to meet Captain Jack Harkness after he hitched a ride on the TARDIS to the end of the universe. Here they encountered the Master and the Toclafane.

Unbeknownst to Martha, her mother, Francine, had fallen under the sway of the Master, who was posing as politician Harold Saxon. When he brought the Toclafane to Earth via a temporal paradox, the Doctor made a secret plan with Martha then allowed her to escape. She travelled across the planet, telling everyone about the Doctor and planning an event precisely one year after the Master took over. This lead to everyone thinking about the Doctor at the same moment, which combined with the Master's telepathic satellite system to enable the Doctor to defeat his old enemy.

With the Toclafane's defeat, time was reversed for the whole world - apart from those who were at the centre of the paradox. This included Martha and her family. She elected to leave the Doctor to look after them - but also because of her unrequited love for him. The Doctor gave her a mobile phone which she could use to contact him in an emergency.

On qualifying as a doctor, Martha found herself headhunted by UNIT, guessing that the Doctor had engineered this. One of her first duties was to liaise with Torchwood Three in Cardiff, over a number of unexplained deaths. These revolved around some clinical trials, and a drug named Reset. This proved to have alien origins - extracted from a huge alien insect. During their investigations, Torchwood's doctor Owen harper was shot and killed. Jack used the "Resurrection Glove" to bring him back to life for a few moments, so everyone could say their farewells to him - but once resurrected he remained so. Martha stayed on in Cardiff to investigate this further. It transpired that Owen had been selected by an extra-dimensional creature - Death incarnate - to allow it to cross over into our universe. At one point the Resurrection Glove drew energy from Martha, turning her into an old woman.

The Doctor was reunited with Martha when she summoned him back to Earth with the phone he had left her. He was travelling with Donna Noble at this time.

Martha and UNIT were investigating the ATMOS factory - producer of a catalytic converter which seemed to have been responsible for a number of deaths across the globe. The company owner, Luke Rattigan, was actually in league with the Sontarans. They captured Martha and cloned her - using her duplicate to work against UNIT. Once the Sontarans had been defeated, Martha was saying farewell to the Doctor and Donna in the TARDIS when it suddenly dematerialised. It travelled to an alien planet in the far future, where Martha became separated from the others. She found herself captured by the piscine Hath. They befriended her when she inadvertently helped them.

Back on Earth, Martha joined forces with many of the Doctor's previous companions and friends after the Daleks moved the planet across space. Martha was going to employ the Osterhagen device - which could destroy the planet to prevent it being taken over- but the Daleks teleported her away to their space station. One of the people Martha met was Mickey Smith, who had been living in an alternative universe for a time. He returned to this Earth after the Daleks had been defeated. 

Martha left UNIT and married Mickey - the pair becoming freelance alien investigators. Just before he regenerated, at the end of his Tenth incarnation, the Doctor saved them from a lone Sontaran.

Played by: Freema Agyeman. Appearances: Smith and Jones - Last of the Time Lords (2007), TW: Reset, TW: Dead Man Walking, TW: A Day In The Death (2008), The Sontaran Stratagem / The Poison Sky, The Doctor's Daughter, The Stolen Earth / Journey's End (2008), The End of Time Part II (2010).

• Agyeman had featured in 2006's Army of Ghosts, playing the character Adiola, who worked for Torchwood One. She was killed by the Cybermen. The Doctor met her, and would have remeberd her - which may be why he singled out Martha to join him after losing Rose, and being turned down by Donna. The resemblance had to be explained, as Smith and Jones followed so soon after Army of Ghosts, and this was that Martha Jones had a cousin named Adiola, who disappeared when Torchwood One was attacked. The Doctor never tells her what really happened to her relative (at least not on screen).