Eden 2 was a virtual level 1 planet used to lure in would-be conquerors and impose the punishments of intergalactic law upon them. The Twelfth Doctor referred to it as an "empty paradise planet".
He took Clara to Eden 2 and found it was under attack from the Vladlack who wished to freeze the entire planet to suit its environment to their needs. The planet fought back and the Vladlack were confronted by an agent of the intergalactic law. They were handed sentences of a thousand years hard labour. The Doctor, in light of the failure to submit transgressors to trial, took issue with the method and used his sonic screwdriver to affect Eden 2's controlling satellite so that, in future, potential visitors would be warned away. (COMIC: Freeze)