A Mirror appears as a glowing green slab or monolith, positioned more-or-less vertically; the perspective is strange. It can remain opaque even when active and ready to accept travelers. However , connected mirrors can also open in a way that allows individuals on both sides to see each other.
Each Mirror has a patterned border, and is typically surrounded by distinctive dot-and-line ornamentation and statues associated with the Great Ancient Civilization. The Mechanicsburg gate has a bracketed torch mounted to one side which appears to spew greenish flame when the Mirror is functioning/open.
Insome quasi-alchemical symbols can be seen on the surface of an inactive Mirror. It's unclear whether they're part of the Mirror itself or were drawn by someone else. No other Mirror so far is shown to have these, or shown this close for that matter.
Queen Albia of England and her sister immortals extensively used these devices to travel and communicate between their various realms during the golden age of their rule, to the point that they often did not know where said realms were more mundanely positioned in relationship to each other.
As old as Albia and handful of other surviving Queens are, the gates are evidently even older, their original creator(s) are currently a mystery, and the network eventually "went dark" and could not be reactivated. This is now known to be at least partly due to the actions of Lucrezia Mongfish, who the Queens through the Mirror network and many mirrors to go dark, one by one, eventually leading to the collapse of the whole network. Albia seems to believe that Queen Sianna for this final collapse of the network, and that she caused the remaining mirrors to go dark in order to impede Lucrezia, but this has not been confirmed. Later remarks by Lucrezia imply that she was responsible.
The mirrors do continue to work erratically. Agatha is unwillingly dragged through a Mirror (AKA the Monolith) located in the depths of Red Cathedral in Mechanicsburg, ending up in The Refuge of Storms. During this process, The Abbess of the Cathedral at one of the Mirror's controls, either activating it or setting its destination. A flashback a scantily-dressed Klaus Wulfenbach carrying an infant while passing through a mirror in rather dramatic and action-packed fashion. It has not been officially confirmed in-comic, but it has been established thanks to external material that the infant is Gil, and the duo's departure-point was Skifander.
Lucrezia knows how to reactivate them, one at a time at least. The process also requires something from the destination point (fragment of Londinium bedrock, for example), which is most likely the reason for Lady Steelgarter's quest to procure a genuine Skifandrian artifact (why would she want to get there is still a mystery). Connection can be established with some inferior energy source (or possibly without it at all), but it'll only allow visuals and sound to pass through. Matter transfer requires an active Queen's Flame connected.
- The Royal Collection of Inconvenient Oddities in Londinium has a (now ) found in an icebound temple in the Alps. (Or so we've been told, all information about this Mirror comes from a source who should be considered unreliable at best.)
- in Mechanicsburg.
- Skifander, Queen Luheia, the city's long-deceased ruler. , finally . This Mirror is labelled as being associated with
- Big Rat Island , reactivated by Lunevka and her cultists.
- Citadel of Silver Light is to have one (called Geister Gate earlier).
- House Mongfish discovered when Lucrezia was a child, location unconfirmed, but possibly near the Mongfish summer home.
- , location and status unknown.
- , seen in flashback.
- , which may be the same as one of the confirmed locations.
- The Collection also contains a which marks the location of Queens (and thus presumably Mirrors) around the world.
- Albia most likely has another one under her more direct control, particularly Queen's Henge. , possibly located in the
- Presumably in Ubar in the possession of its Queen Ishtar-Re.
- An The Refuge of Storms, presumably destroyed. (GURPS supplement claims it wasn't a gate proper, but a device spoofing the channel, and it connected only to the Monolith above) version located in
Almost every Mirror has a pattern around the arch, which, assuming the depictions are consistent, assists in identifying a particular gate.
During the semi-canonical side-story Cheyenne) set at Transylvania Polygnostic University, we learn that the ancestor of the Heterodynes, Ghengis Ht'rok-din, made full use of strongly resembling the Mirror network, in particular when he won the so-called Two-Hour War by attacking with the advantage of surprise. A student also mentions a map of Ley-Lines, which may be a map of the entire network or relate to something else as yet not mentioned in the adventures. The gate which actually appears "in person" in this story shares similar carvings on the surrounding wall as the ones seen elsewhere, but appears to have an entirely different gate mechanism powered by an inserted orb and allows for time, rather than distance travel.(Illustrated by
Possibly Relevant Outside Information
In the non-GG world, there is a "gate" visually connecting Dublin to Vilnius.