Series 3 (2007)
Episode title: The Lazarus ExperimentFeaturing: Tenth Doctor
Companions: Martha Jones
First shown: 5th May 2007
Related articles: Professor Lazarus
Guide: The episode starts with the Doctor landing the TARDIS in Martha Jones' flat, London, ready to drop her off home after her reward.
Martha departs from the TARDIS and turns on the news, in time to hear a news release about someone called Lazarus, who has found a way to cheat death. The Doctor leaves, but then returns almost immediately, because he is now interested in this Lazarus.
Tish, Martha's sister, has a PR job with Lazarus, and has been able to get the entire Jones' family into the event for free. This is where Martha's mother, brother and sister meet the Doctor. He is received well by Martha's brother and sister, but not by her mother.
The Doctor watches Lazarus step into his machine, looking very old. After a few moments of machinery sound, he steps out, looking about 30. Regenerated, he says. The Doctor is very interested now, and goes off to speak with Lazarus, but instead finds the dead body of Lazarus' assitant.
Martha learns that Tish has gone on the roof with Lazarus, and she and the Doctor goes after her to warn her. Tish however tells Martha that she is just jelous, but soon realises the truth with Lazarus changes into a large spider like monster.
The Doctor concludes that the machine must have awoken some dormant gene in the human system, one that evolution had got rid off, but still there, sleeping. But it needed a lot of energy to sustain it, which is why if fed off human energy.
The Doctor and Lazarus go into a chase scene into a church, but Martha and Tish provide a distraction, making Lazarus chase them, while the Doctor goes off to the organ. When Lazarus is up high, trying to push Martha off the edge to the floor of the church, the Doctor plays the organ at amplified sound level (with the help of the sonic screwdriver).
Lazarus falls down instead, and dies on the floor of the church. The episode ends with Martha's mother slapping the Doctor, and the Doctor going off into the TARDIS. He offers Martha the chance to come with him, but she refuses, not wanted to be extra luggage, but he says permenantly, and they go off together for the next adventure.