Agelaos

Agelaos was a colony on the farthest reaches of the Second Great and Bountiful human Empire.

Astronomical Data
Agelaos was colonized for the wormhole that opened into the Time Vortex. The skies around the wormhole were full of auroras, shooting stars and ion cascades. The planet itself was covered in ice and snow, shaped into impossible looking shapes. (NSA: The Story of Martha: The Weeping)

History
During the Second Great and Bountiful human Empire, 20,000 colonists came to Agelaos and attempted to terraform the planet, using the wormhole as a power source. They started to develop psychic powers from the wormhole, specifically precognition. Unfortunately, the wormhole also infused the inhabitants with alien DNA, causing them to develop into bizarre mutation. The source of these "monsters" was unknown, so the government was forced to quarantine the planet. They appointed Waechter to man a beacon to warn off any incoming ships. He was cybernetically connected to the Beacon, keeping him alive and incidentally keeping him clean from mutations.

Waechter watched over the beacon for 500 years, until the Tenth Doctor and Martha came to Agelaos. The Doctor was able to break the connection Waechter had with the Beacon, allowing him to leave the planet, but this also allowed the mutations to take affect. Waechter decided to allow the Doctor to sever the connection completely, completing the mutations and allowing him to live with the other "monsters". (NSA: The Story of Martha: The Weeping)