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.

In 2059, while escaping from Bowie Base One, she was infected by the Flood when the viral water touched her body after being trapped.

Early life and career
Steffi was born on September 3rd 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 (2046). After that, she worked at Argonne National Laboratory (in 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.

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 look through the medical dome camera at Maggie, and Steffi wonders what she has become. She calls Adelaide over the comlink, begging her to come back, but Adelaide orders Ed to make sure that Maggie is contained.

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 climb the maintenance shafts in the main dome, walk to the centre of the roof of the control centre, fall to their knees and exude more water from their hands and mouths through the girders in the roof. The water quickly pours into the room, separating Steffi from the rest of the crew and 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. Captain Adelaide Brooke said to her that she will let her out through the back of the section. Knowing she soon would be infected, Steffi watched a video of her two children just moments before the water came into the section. Steffi cried as the water gushed into the section, and Mia and Adelaide watched in horror as she was infected and began jittering. Adelaide escaped with Mia Bennett after the infected Steffi came out of the section. Following her transformation, Steffi and the other infected personnel went to the glacier and screamed so they could crack the ice. Steffi and the other infected personnel were killed when Adelaide blew up the entire base.

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.