on Line Sigma

Overview

Line Sigma is a vertical tram line, secured corridor, and designated zone of confinement whose full extent has never been surveyed in a single sitting. It is administered by Jurist Sigma-1, whose sole jurisdiction is the line itself, and it is entered chiefly by way of Stairwell Sigma-44, though the stairwell and the line have disagreed about their junction since the rerouting.

The line was rerouted under the Reroute Authorization for Line Sigma, also cited as Authorization Sigma-12. Under the terms of that document the corridor is described as "secured, and secured again upon inspection" (Reroute Authorization for Line Sigma, Clause 3). Inspections of the second securing are conducted by the Sigma Regulator, which also certifies atmospheric conditions along the line prior to any sanctioned activity. No sanctioned activity may proceed on an uncertified atmosphere, and at least one has.

Line Sigma is classified Sigma-class throughout. All Sigma-classified personnel and materials moving along it do so by means of the Vertical Tram Line Sigma, a suspended cabin system governed by the Line Sigma Master Line and overseen in operation by the Functionaries of the Final Line.

Route and structure

The line is vertical, and this is the only property on which every account agrees. Its segments are recorded by the aperture or stairwell at which they are entered rather than by elevation, since elevation measurements taken from the line's own cabins return figures that vary with the passenger. The Aperture Sigma-7 stairwell serves the upper recorded reaches; the lower reaches are served by Stairwell Sigma-44, which was rebuilt to meet the rerouted line and has never sat flush with it.

At its confluence with the line stands the Delta-Sigma Capillary Cluster, a junction of sufficient complexity that the Capillary Clerk's Office maintains its own copies of the line's diagrams rather than request them. The origin point of the line is occupied by the Sigma-Chron, which is housed there and only there, and which no instrument has been permitted to measure since the Seventh Concordance assigned it to the custody of the line itself.

The Dock Sigma freight apron adjoins the line at an elevation the dock's own records decline to state. Peregrine-Sigma objects — which must be operated exclusively on Line Sigma — are received at the apron and nowhere else.

Governance and the Master Line

Authority over the line is divided between the Line Sigma Master Line, which sets the schedule, and the Functionaries of the Final Line, who execute it. Jurist Sigma-1 rules on disputes arising between the two, and on no other matter whatsoever; an attempt in the winter of the year recorded as 4 Sigma to extend the Jurist's jurisdiction to the apron was refused on the grounds that the apron "is not the line, however much it leans" (Jurist Sigma-1, Ruling 19).

The Operational Consent is required before any cabin is moved with occupants aboard. Consent is issued by seal and not by signature, and a seal applied to the wrong face of the document is void. The Scriptorium of the Final Line has pressed for a ruling clarifying which face is correct; none has issued, and the practice among Functionaries is to seal both faces and let the record show an excess.

Copies of this article's sources vary. Vellum Grade 4 is the grade specified for all duplicate schedules of the line, though the Scriptorium has for some years used a lighter stock on the grounds that the schedules are read aloud and then discarded.

The confinement question

Line Sigma is a designated zone requiring confinement for Sigma-class phenomena, a designation that predates the rerouting by an unknown margin. What confinement means in practice on a vertical corridor is the subject of the archive's longest-running disagreement. The Third Concordance holds that confinement on the line is vertical and continuous, and that a phenomenon is confined when it cannot leave the line at either end, neither end having been found. The Fifth Concordance, Annex Sigma, holds instead that confinement is lateral, and that the line's walls perform the work in their entirety.

"A phenomenon that has left the line has, by that fact, demonstrated that the walls were lateral and insufficient. The correct response is to amend the walls, not the Concordance."

— Fifth Concordance, Annex Sigma, marginalia in the hand of the Archivist of the Lower Reaches

The practical consequence is that two confinement registers are kept, one counting phenomena that have not left vertically and one counting phenomena that have not left laterally, and their totals have never matched. The discrepancy is currently 41 and is considered stable. The Sigma Regulator certifies the atmosphere in which the counting is done but takes no position on the count.

Incident of the uncertified descent

In the winter recorded as 4 Sigma, a Functionary of the Final Line descended from the Aperture Sigma-7 stairwell to the Delta-Sigma Capillary Cluster without prior atmospheric certification, on the stated belief that the certification for the preceding day remained in force. It did not; certification expires at the close of the shift in which it is issued, a rule the Functionary's own office had drafted. The descent was completed without injury and with the loss of one glove.

The subsequent inquiry produced two findings. The first, filed by the Regulator, held that the atmosphere had in fact been within tolerance, and that the violation was procedural only. The second, filed by Jurist Sigma-1, held that an uncertified atmosphere is uncertified whether or not it is breathable, and that the distinction between procedural and substantive violation is not one the line recognizes. Both findings stand. The glove was never recovered and is not counted among the 41.

Access

Entry to the line is restricted to Sigma-classified personnel and materials. Visitors are permitted only in the company of a Functionary, only between the hours posted at Stairwell Sigma-44, and not during certification. Writing materials may be carried; ink may not. The rule is old, its purpose is no longer recorded, and it is enforced at the stairwell head without exception.