It was evacuated over the two days following the battle.
Some time after Amy's honeymoon on-board the Doctor's TARDIS, she was captured by Kovarian's alliance and replaced by a Ganger so perfectly synced to her that neither the Eleventh Doctor nor Amy's husband, Rory, would notice.
As far as Amy knew, she was continuing her adventures with the Doctor and Rory. In reality, Amy was taken to Demons Run in the 52nd century, where her pregnancy came to full term. The Doctor realised what had happened and terminated her Ganger. Amy woke up on Demons Run, just before giving birth to her daughter, Melody Pond. (TV: The Almost People)
The Doctor assembled an army of allies from many races and time periods, while Rory attacked the Twelfth Cyber Legion to intimidate Amy's captors. A month after Amy woke, Demons Run was attacked by an army of Silurians and Judoon led by Sontaran Commander Strax. A squad of spitfires destroyed Demons Run's communications array so the alliance could not call for help. The Doctor, Madame Vastra, and Dorium Maldovar raided the computer records left behind, discovering surprising information about Melody. The forces under Colonel Manton surrendered, but this was a trap for the Doctor; after most of his forces had withdrawn, the holding forces were slaughtered by the Headless Monks. Only the Doctor and a few friends survived and Melody Pond was spirited away by Madame Kovarian. River Song appeared after the battle to reveal her identity to the Doctor, who left the base before telling River to return Vastra, Jenny, Amy and Rory to their own time. (TV: A Good Man Goes to War)
Two days after the battle, Madame Vastra and Jenny returned to Demons Run to recover the seemingly deceased Strax. They woke him up and revealed that he had not died since they had used alien technology to heal his wounds. Jenny explained that he had never truly passed away thanks to the resurrection technology and he had been in a state of unconsciousness for two days while the resurrection device healed him. Though Strax was angry about not having died, Vastra and Jenny announced that the station was being evacuated, and offered to take Strax with them back to Victorian London. Strax was hesitant and at first rudely refused but then changed his mind and agreed to accompany them. (WC: The Battle of Demon's Run: Two Days Later)
The etymology for the asteroid's name, according to Dorium Maldovar, came from the saying, "Demons run when a good man goes to war," possibly hinting at the battle of Demon's Run.
The following poem also used the saying:
- Demons run when a good man goes to war.
- Night will fall and drown the sun,
- When a good man goes to war.
- Friendship dies and true love lies,
- Night will fall and the dark will rise,
- When a good man goes to war.
- Demons run, but count the cost.
- The battle's won but the child is lost.
Behind the scenes
The name of this location has been spelled two different ways with and without an apostrophe. On signs that appear on screen the name is written without an apostrophe as "Demons Run". However the on-screen titles display it as "Demon's Run".