Oneiric Fugues

Oneiric Fugues are sustained, self-propagating passages of dream-matter in which a single motif is restated across successive layers of a sleeping mind until the restatement acquires independent duration. They are catalogued by the Dream Registry under Class 3(b), "Recursive Affective Passages," and are distinguished from ordinary Oneiric Resonances in that a fugue does not merely repeat — it answers itself. The distinction matters chiefly to insurers, who have argued about it since the winter of Floor 1188.

Definition and morphology

A fugue consists of a subject (the originating motif), one or more answers (restatements at altered interval), and a stretto, in which answers begin before the preceding statement has concluded. Where the stretto exceeds four overlapping answers, the passage is reclassified as a crowded fugue and may not be deposited without annotation in Oneiric Blue, per Eleventh Concordance, Annex 6.

Subjects are recorded on the Oneiroscone and assigned a sigil under the Oneiric Decimal System; the first three digits denote the Core Affective Triad, so that a fugue built on a subject of grief-and-ceremony is legible at a glance to any licensed reader. Fugues with more than two answers frequently defeat this glance.

The Floor 1188 restitution

In the winter of Floor 1188 an unattended fugue on the subject of a doorknob — a trivial subject, three notes, catalogued in under a minute — accumulated nineteen answers over eleven hours and was found to have generated a working corridor, complete with draft, that terminated at a wall which had not previously been surveyed. The Register of Reported Oneiric Phenomena records the finder's account without embellishment:

"I walked the passage expecting to arrive at the stair. I arrived at the passage. I walked it again and arrived at the passage. On the third attempt a Librarian met me halfway and asked that I stop, as the fugue was answering me."

— Register of Reported Oneiric Phenomena, entry 1188–04

The corridor was dissolved by dampening the following morning. Two of its bricks were retained and are held in the Map Room as evidence; they are not to be handled, as they continue to answer one another when moved apart.

Classification disputes

The Oneiric Taxonomies classify Class-3 Oneiric Artefacts by provenance, which is to say by the chamber in which they first condensed. Fugues, being passages rather than objects, have no fixed chamber, and the Department of Ephemeral Taxonomies has twice proposed that they be reclassified as events, which would place them under the purview of the Dream Canals inspectorate.

The Fourth Concordance (Annex 2, cl. 14) states flatly that a fugue "is a thing and is to be stored as a thing." The Ninth Concordance (Annex 2, cl. 3) states with equal flatness that a fugue "is not a thing and is not to be stored, but is to be allowed to conclude." Both are in force. The standing practice, unrecorded in any document but universal among the dockers of the Lower Depository, is to store a fugue if it was found and to allow it to conclude if it was heard.

The Metrical Recension

A minority reading, advanced by the archivist Sabel Quint of the Fourth Scriptorium in her commentary on the Oneiric Register, holds that a fugue cannot properly be said to exist until it has been transcribed, and that untranscribed fugues are merely "loud weather." The Librarians have neither endorsed nor censured the reading. Quint's commentary is nonetheless shelved with the primary texts, which some take as a ruling and others as a convenience of space.

Interaction with other phenomena

Unmanaged fugues are a recognised source of Oneiric Feedback, and the feedback they produce is of the resonant cartographic subtype, since a fugue that has generated a corridor has made a map of itself. Ætheric Earplugs mitigate the auditory overspill of a stretto but do nothing for the passages, a limitation noted in the earplug dispenser's own label and widely ignored.

Fugues are also the commonest vector of Oneiric Cross-Contamination on floors where more than one chamber is sleeping, because an answer does not respect a chamber wall. Oneiric Integrity Screening requires that adjacent chambers be screened before a crowded fugue is deposited; in practice the screening is performed by the depositor, who is asleep.

Handling notes

Fugues are carried with the subject muffled and the answers counted aloud at each landing. A depositor who loses count is required to place the fugue on the floor, step back, and begin again from the subject. The inventory of a fugue crate is short and standard: the subject, sealed; the answers, numbered; a counting cord of the correct length; and one silence ledger per crate, unopened unless the stretto runs.

Where a fugue is heard but not found, the floor is closed to traffic and the fugue is permitted to conclude on its own schedule, which is not recorded on the closure notice. Floors 402 and 403 have been closed to traffic since the spring of 1104 for this reason. The notices at their stairheads are repainted annually and remain accurate.