Demons Run

Demon's Run was an asteroid used as a military base by Madame Kovarian, the Anglican Regiment of the Church and the Headless Monks. Amy Pond was held prisoner and gave birth to her daughter here. Soon after, it was the site of the Battle of Demon's Run, in which the Doctor attempted to rescue Amy and her baby.

History
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 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 Demon's 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 Demon's 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, Demon's 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 The forces under Colonel Manton surrendered, but this was a trap for the Doctor; after most of his forces had withdrawn, the holding forces were slaughtered by the Headless Monks.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 had been spirited away by Madame Kovarian. River Song appears 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. It is unknown if the clerics returned to the base or if it was left abandoned.

There was a saying that went with Demon's Run: "Demons run when a good man goes to war." There was also a poem:


 * 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.


 * (TV: A Good Man Goes to War)