Every RPG campaign needs an adversary, in the Infinite Worlds setting one option for an adversary is Centrum
Unlike Homeline, Centrum is ruled by a single world government, and has a unified technocratic English-speaking culture across the entire planet. Centrum is a totalitarian, homogenized world-state, and the only world other than Homeline to have a major parachronic program.Centrum is a socialist technocratic meritocracy; the government provides all employment and handles the economy, which is bolstered by the massive resources acquired from other worldlines. They believe other worlds should be aiming to follow their example and have a dedicated program of supporting political and economic groups that reflect their own values -- stability, meritocracy and an unconscious prejudice toward speakers of English. They view the mix of competing government agencies and private companies from Homeline as dangerously anarchic. From a Homeline perspective Centrum seems authoritarian and repressive, whilst from a Centran perspective Homeline seams anarchic and unbalanced - with serious social problems from which Centrum does not suffer.
Its point of departure was in 1120, when the White Ship carrying William the Aetheling, the heir of Henry I of England, did not hit a rock in the English Channel. William's survival precluded The Anarchy and the Hundred Years War, and ultimately the "Anglo-French Empire" became a world-spanning power, with technological progress centuries beyond that of Homeline.
However, in 1902 unknown rebels decapitated the ruling house by detonating a nuclear device in London. The resulting succession wars (which included nuclear and biological weapons) wiped out much of humanity and reduced most of the survivors to preindustrial barbarism. But Terraustarils (Homeline Australia) escaped much of the destruction, and the techno-military cabal known as "The Centrum" that took control there ultimately extended its authority across the globe. In 1922, Centrum built their first conveyor and went exploring.
Centrum is located three quantum levels away from Homeline, and as such the two worlds cannot directly send travelers to each other. As a result, both parties fight out their war in the Quantum 6 in-between (and to a lesser extent, in the Quantum 7, as Centrum is attempting to shift Homeline Quantum 6 echoes towards itself for the purpose of denying Homeline access to those worlds and "saving" their populations from Homeline anarchy. Homeline (Secundus) was discovered in 2105 and the cold war with it began.
This is a close parallel of Centrum that is dealing with the Homeline that was described in GURPS Time Travel. It has the same year (2015) as the Homeline it has to contend with which it discovered in its year 2003 and visited via a captured Homeline parachronic conveyor. In 2007 the “Dimension war” became overt.
It knows 600 accessible timelines with Quantums 9 and 10 having 40-50 each, Quantum 8 having 46, Quantum 7 having about 100 and the rest being in Quantum 6 with about half being echos.
Centrum is able to access Red Moon, a Quantum 5 reality. However it unclear how Centrum is able to do this and Infinity seems strangely unconcerned about this little fact.