The Conjoiners are a human hive-mind based faction that operates in various star systems, including Yellowstone. Conjoiners are characterised by the neural implants they carry that boost speed of synaptic firing, as well as allowing mind to mind linking, a process known as Transenlightenment. The Conjoiners are one of the most advanced human factions in colonised space, inventing methods of time travel, inertial suppression, among other technologies.
The Conjoiners were the results of experiments done on Mars by Galiana, the first Conjoiner. These experiments were an effort to "enhance the human brain... for the greater good of humanity." These experiments mimicked the development of early computers:
First, the rate of computation in the brain was advanced - microscopic machines entered the brains of her test subjects and laid down connections between brain cells which exactly mirrored the pathways already in place. Through use of drugs or other machines, normal synaptic firing was halted, and neural processing was handled by the new "loom" of machines. This resulted in highly accelerated thought processes of up to fifteen times faster than normal thought - although at an early stage, the process could not be maintained for more than a few seconds of real time due to the mass build up of heat that resulted from the machinery. By 2605, Conjoiners had bio-engineered themselves cranial crests through which blood could be pumped in order to dissipate heat, and at least some were running at ten to fifteen times the norm at all times.
The next step in Galiana's experiments was the linking of different minds through data-corridors, allowing the sharing of memories, experiences and even mental tasks, such as pattern recognition. However, this was the main cause of concern that baseline humanity had with the Conjoiners; the uncontrolled formation of data-corridors, and the subversion of pre-existing neural hardware for use in the Conjoiner machinery, led to Transenlightenment.
The third and final step was the coupling of human mind with quantum material, in order to link with infinite copies of each individual in parallel universes. This process was called Exordium, and was intended to allow for highly increased cognitive functioning. This was accomplished through use of a magnetically suspended bar of rubidium that was being continually elevated to quantum coherence and collapse, which the subject mind was linked to. On some occasions, when the bar collapsed to a single macroscopic state, the linked mind was placed in a state of superposition with other parallel-worlds counterparts. However, the experiments also resulted in the unexpected formation of a corridor into the future, from which messages could be heard.