The Parnaeum was a power source which was installed in the Stagnant Pond by a woman, who placed a paradox shield around it so that it could not be removed by anybody in existence. It anchored the Stagnant Pond.

Norton Folgate ensured that Andy Davidson saved Gideon Lyme's life so that, as a paradox, he would be able to get through the shield and remove the Parnaeum to power Andy's vortex manipulator. Having done so, Norton could then use the manipulator to save London from the mushroom creatures. (AUDIO: Parasite)