Captain Lundvik was an astronaut. She was in command of a mission in 2049 to the Moon to blow it up with nuclear bombs, because its increased gravity was causing chaos on Earth. When her crew of two discovered the Doctor on her spaceship, she decided not to kill him.
Lundvik showed the Twelfth Doctor, Clara and Courtney an old Mexican Moonbase, whose crew had disappeared in 2039. After both Duke and Henry were killed by spider germs, the Doctor deduced that the Moon was an egg, harbouring a baby alien being inside. Lundvik asked the Doctor how to kill it, and he responded in disgust, appalled at such a thought.
After the Doctor left angrily, Lundvik came into contact with McKean, a man with a new haircut down on Earth. He allowed Clara's message to be broadcast to the whole planet. Clara asked Earth if they chose to kill the baby or allow it to live. The overall response was "kill the moon."
It was then that the Moon started to shake and crack open, and the Doctor took them to Lanzarote, where they watched the alien spring open and lay a new egg. The Doctor sent Lundvik to NASA. (TV: Kill the Moon)