Planet located on the outer edge of the Pegasus Galaxy. This world was selected to play an important part in the McKay-Carter intergalactic gate bridge, linking the Pegasus Galaxy to the Midway Space Station (and from there, to Earth).
The planet was selected because of its proximity to the first Stargate to be placed in a chain in the void between galaxies, and because it was not inhabited – eliminating any traffic interference from locals using their gate. An automated dialing procedure allowed Atlantis to dial M4F-788 and forward gate traffic on to the next gate in the chain rather than reintegrating travelers and allowing them to exit on the planet.
When the Wraith discovered the planet and the existence of the Stargate bridge, they visited this world in order to hack into the bridge network and access Midway Station.
M6R-125 is in the Ancient database in Atlantis.
HOME TO - Uninhabited
FIRST APPEARED - Midway
Midway - After "Todd" passes on intel he stole from Atlantis, the Wraith hack into the Stargate bridge using the D.H.D. on M4F-788.