(Note: sometimes descriptive books are referred to as linking books as well, but strictly speaking, that usage is not correct, as there is a distinction between the two.)
Linking books, or korvakhtee, in the
M/R/D/E world, were written by the
D'ni using special materials (ink and paper among them), and a
(presumably) standard format for the text, which would allow the
user of the book to link to the place where it was written. A
linking book works by creating a small tunnel of sorts to the
between-universe link of the descriptive book (kormahn) for
the destination Age. Thus, if the descriptive book were
destroyed, all linking books written in that Age would stop
working.
Though there is still some debate, it is generally considered
impossible to link directly between places in the same Age;
therefore, a linking book is not useful immediately after it is
written; it must be taken out of the destination Age
first.
There are a few good reasons for using primarily linking books rather
than descriptive books to link:
- Linking books are easier to produce than descriptive books. The
consensus is that it is not necessary to have any knowledge of the
descriptive book for an Age when writing a linking book to a place
within it; thus, the standard formula suffices.
- Linking books are smaller, and thus lighter, than descriptive
books. The standard formula used for linking books does not include a
description of the entire Age, as it is necessary to include when
writing descriptive books; thus, linking books are more portable.
- Linking books are less precious than descriptive books. If a
descriptive book is lost or destroyed, essentially the entire link
to the Age is lost. Linking books to the Age will no longer
function, and even copying the words verbatim into a new descriptive
book has an infinitesimal probability of linking to the same
Age.
- Linking books are more precise location-wise. The initial link
to an Age (through a descriptive book) might link to nearly any place
in the Age (though there are some general heuristics), whereas
linking books always link to the exact spot in which they were
written.
When linking away from your homeworld, one of the cardinal
rules of thumb is to always bring
along a linking book back to your previous location.
There is some debate regarding how any linking books could be created
to the original D'ni homeworld, Garternay, as no descriptive
book had been written for it. Some of the solutions proposed so far
include:
- There is a third type of book (name unknown), which acts like a
linking book but does not require a descriptive book to exist. This
raises the problem of why these books were not used more often;
however, it is very possible that these books took even more work than
descriptive books to write, and so would only have been used for
Garternay, after which the practice was abandoned.
- Time is circular, and there was in fact a
descriptive book for Garternay.
Primary sources:
- Colin Wilson's Gehn's Book problem, at
<http://www.dur.ac.uk/~dph3cdw/gehn.html>
- Colin Wilson's Mechanics of Linking, at
<http://www.dur.ac.uk/~dph3cdw/linkmech.html>
- The MYSTcommunity forums, at
<http://www.mystcommunity.com/forum/>