Steffi Ehrlich

Steffi Ehrlich (2021-2059) was a German member of the group on Bowie Base One from July 2058 to November 2059. She was the senior technician of the crew.

Early life
Steffi was born on September 2021 in Iserlohn, Germany. After attending secondary school in Iserlohn, Ehrlich spent two years in the Bundeswehr. In 2042, she then went on to study physics at RWTH Aachen University, taking a doctorate in solid state physics in 2046. After that, she worked at Argonne National Laboratory at Chicago and the University of California at Berkeley. In 2048, she was selected to join the German astronaut team in the European Space Agency. She completed basic training at the German Aerospace Centre between 2048 and 2050.

She was part of the crew for the tenth German Moon mission in the spacecraft AWARQ. In 2051, she married her childhood sweetheart, Hans Stott, and had two children Ulrika and Lisette. (TV: The Waters of Mars)

Colony on Mars
Shortly after her second child was born, she was selected for the Bowie Base One mission. She initially refused to leave her family but changed her mind after an unspecified event that devastated many parts of Germany. She and the other members of Bowie Base One met the Doctor on 21 November 2059, the same day the attack on the the Flood began.

During the Flood invasion, Steffi witnessed three of the crew become zombie-like water monsters. After Margaret Cain was infected, Steffi, Mia Bennett and Roman looked through the medical dome camera at Maggie, with Steffi wondering what she had become. (TV: The Waters of Mars)

Infected by the Flood
Just as Steffi and the other members of the crew were preparing to escape, the infected Andy Stone and Tarak Ital climbed the maintenance shafts in the main dome, walked to the centre of the roof of the control centre, fell to their knees and exuded more water from their hands and mouths through the girders in the roof. Water quickly pouring into the room managed to separate Steffi from the rest of the crew, trapping her, with the Flood attempting to break into the room. She hid in Section 9 of the main hub and was unable to get out.

Knowing she soon would be infected, Steffi watched a video of her two children just moments before the water came into the section. Crying as the water gushed into the section, Mia and Adelaide witnessed her becoming infected. Following her transformation, Steffi and the other infected personnel went to the glacier, and screamed in order to crack the ice. Steffi and the other infected personnel were killed when Adelaide blew up the entire base. (TV: The Waters of Mars)

Behind the scenes

 * The details of her pre-Bowie Base career can be briefly seen in her obituary.
 * The obituary article was cut off, only stating that she said, "I don't want to live here any longer".
 * Like the other female member of the Flood, Margaret Cain, she kept her eye colour. It seems the males had milky, blue eyes while females kept their colour. The Doctor noted this during the episode and suggested that it meant she was closer to human than the others.