‘Psi’ is the catch-all common name for a very broad category of often inexplicable effects resulting from the minds of sentient creatures infected by the Sagittarius Signal. Although understanding of these effects is limited, and in many cases simply trying to understand the mechanisms of psi is enough to trigger the infection, a tentative body of knowledge has been collected, predominantly in the vaults of Neptune and in the far Oort Cloud.

The general consensus holds that psi abuses the manner in which some esoteric forms of computation cause ‘ripples’ in neighboring continua in order to manipulate our own continuum by proxy. This has led to the development of psi-enhancing computerized devices such as psi-amps and a series of astonishingly illegal cerebroenergetic enhancers that can turn a moderate to advanced operant psychokinetic into the human equivalent of a capital ship railgun.