Cygnus is more than just a sector. It is a region of space dominated by a peculiar local physics that seems designed to both challenge the strong and protect the less capable. This area of effect of subtly altered physics is dubbed the 'Trinity Zone'. The boundary of Cygnus is not clear-cut but rather defined by the amorphous edge of the Trinity Zone, and the space between the Zone and the neighboring sectors is known as the 'Horizon.' The Horizon is marked by fluctuating physics, making it difficult to travel through by most forms of FTL travel and making all forms of magic there unpredictable at best. The CSA operates a number of small listening posts on the Horizon, however these are almost entirely in regions that border other sectors, and most of them are unmanned.

The origin of the Trinity Zone is unknown, though it is not believed to be an artificial construct. Its effect, however, cannot be denied. Almost every form of faster-than-light travel fails upon entering the Trinity Zone. The space within the zone is highly resistant if not impervious to electron tunnelling on a macro scale, space fold/warp, and subspace phasing and transdimensional shift phenomena. The only means of entry into the sector is by jumpspace, and this has had a pronounced effect on Cygnus in that jumpgates or jump engines must be constructed in order to travel between Cygnus's stars and/or the galaxy outside the sector. The most significant exception is the 61 Cygni system, also known as Gateway. This system is on the very edge of a 'metastable' section of the Horizon, and a well-known and -charted route leads from just outside the sector to Gateway. Travel from Gateway to any other Cygnian system still requires jumpspace travel, however. Current theories on the astrography of the Trinity Zone seem to indicate that one or two additional systems may also be similar to Gateway, also known as 'loran' systems.

The Trinity Zone also has the characteristic of being null-mana, in that 'free mana' is not available. In many places, in fact, it is mana-negative, draining and reducing magickal effects. However a very few places, most notably on Tharkold and in some places on the Horizon, are mana-positive, and there are likely a very few 'wild mana' area, though these would be exceedingly rare.

In addition, there are vague theories proposed that the portion of the metaversal probability manifold enclosed by the Trinity Zone is 'metastable' and resistant to most forms of manipulation. The presence of Hawking radiation, and no visible untoward effects upon Cygnus sector's population, would indicate that either this theory is science fiction, or applies only to certain forms of manipulation of probability.

There are further effects of the Trinity Zone that are still being studied. The examination of the zone is the primary mission of the survey ships CSA Beagle and CSA Calypso, and Outpost Mediterranean.

In shape the Trinity Zone, and thus Cygnus sector and, by definition, the nation of Cygnus, is very roughly spherical or ovoid, with a slight extension out towards the interglalactic Reach. This region is significantly devoid of stars and is called Star's End.