Double nexus particle

The double nexus particle, Findecker's Folly, was a particle discovered by the scientist Sa Yy Findecker at some point in the 51st century. While one nucleus existed in the material universe, the other mirror nucleus existed outside of time and space altogether. (AUDIO: The Butcher of Brisbane)

It led to the development of practical time travel through the formation of zygma energy into a beam as a power source applied to the time cabinet. However, it ultimately proved to be a technological cul-de-sac, as time travel in this way led to horrible and life-threatening mutations. The only way to stay alive though it made the process worse was to drain the life energy of other people. There was no other cure. (TV: The Talons of Weng-Chiang)

When Romana visited Magnus Greel in his bunker in Reykjavik, she called the double nexus particle "rubbish". (PROSE: Under Reykjavik)