Erica (The Pyramid at the End of the World)

Erica was a human woman living in Yorkshire in the early 21st century. She worked as a scientist at Agrofuel Research Operations. (TV: The Pyramid at the End of the World)

Biography
When she was little, Erica wanted to be a bus driver. She said it was because "she liked the way people smile at bus drivers". At some point she decided to become a scientist and got a job at the Agrofuel Research Center in Yorkshire.

In 2017, while going to work one morning her husband accidentally broke her glasses, impairing her sight.

When she got to work, she inspected a project involving plants with her colleague Douglas. However, when they had to program what chemical agent to spray onto the plants, she asked Douglas to do it. But as he had been drinking the night before, his sight was reduced too. He typed in the decimal point of the numbers incorrectly and this created an extremely virulent new bacteria unlike anything on Earth.

When they inspected the plants again, they found them disintegrated. After they took samples and found the bacteria, they immediately began evacuating the building. However, Douglas had exposed himself to the bacteria and Erica watched in horror as it dissolved his body and killed him.

When her colleagues had fled the building, Erica was the only one who stayed behind to try to stop the bacteria from getting released into the atmosphere by the automatic venting system. The Twelfth Doctor then appeared from the TARDIS. Though they had only just met, Erica was quick to trust him and briefed him on the situation.

The Doctor decided to blow up the lab to incinerate the bacteria before it could get out, but once he set an improvised bomb, he found himself unable to get out due to his blindness. Bill Potts thus pleaded with the Monks to restore the Doctor's sight, which they did. The Doctor was able to escape just as the lab exploded, killing the bacteria and saving the Earth, though at the price of handing the planet over to the Monks. (TV: The Pyramid at the End of the World)

Personality
Erica seemed shunned at work because of her short stature. However, she got on well with her colleague Douglas and was horrified when he was painfully killed by the bacteria. Nevertheless, she did not let her emotions get away from her and managed to maintain a calm and level-headed attitude when facing danger. In fact, when her colleagues had fled, Erica was the only one who stayed behind to try to destroy the bacteria, indicating both dedication and bravery. She was also quick to trust the Doctor despite having just met him and even shared humorous exchanges with him, possibly to alleviate the dire situation she was facing. (TV: The Pyramid at the End of the World)