Dust motes drift through shafts of pale, sourceless light that filter from high, cracked vaults. The walls are pure dwarven work—thick granite blocks carved with the old clan marks of Kadrel Karad—but every surface is now veined with thin black cracks that pulse faintly, as though something abyssal still seeps through the stone. In the exact center of the chamber stands a great cosmological dial: a ten-foot-wide disc of blackened iron and fractured crystal, its concentric rings etched with interlinked symbols of the Material Plane, the Astral Sea, the Ethereal, the Abyss, and a fifth ring marked with an alien glyph. Five shallow alcoves circle the room; each holds a dormant oval of swirling mist that once served as a planar portal. Resting on a small stone pedestal beside the dial is a slim, leather-bound journal written entirely in Undercommon, its pages filled with precise diagrams of the rings and terse notes in the same script. The air smells of ozone and old dust.The Challenge – “Align the Fivefold Path” “Align the Fivefold Path”
The dial controls the five linked portals (this room plus four others deeper in the complex). It can no longer open true planar gates; it only cycles the five local portals between Sealed, Stable, or Unstable. The journal contains the exact alignment sequence and warnings written by the illithid who last calibrated the device. Goal Use the journal (or clever work-arounds) to set the correct ring positions so one stable portal opens and the sequence for the other four linked rooms is revealed. Multiple valid approaches
Translate the journal
The journal is written in Undercommon. Speak Language (Undercommon) or Comprehend Languages lets a character read it freely. Decipher Script DC 20 (or Knowledge (dungeoneering) DC 18 if the reader has dealt with illithid texts before) extracts the full alignment sequence and the warning about unstable surges. Once translated, setting the rings is straightforward (no further checks required).Partial translation / diagram reading
Even without full language skill, a character can study the diagrams. Search or Knowledge (the planes) DC 15 identifies which symbols must line up. This gives enough information for a partial solution (three of five rings correct).Mechanical approach
A character can ignore the journal and work the dial directly. Disable Device DC 22 (or Open Lock treated as a complex mechanism) lets them lock the rings into a stable configuration by feel and trial. Failure by 5 or more triggers a minor energy surge (see below).Brute-force / trial-and-error Characters may simply rotate rings and test the portals. Each full incorrect cycle causes a small surge of residual abyssal energy ( negative energy damage to everyone within 10 feet of the dial, no save). After two or three attempts the correct alignment can still be found, but the cost adds up.
Partial success & failure costs
Full success (correct sequence from the journal or perfect mechanical work): One stable portal opens. The full five-room sequence is now known to the party. Crossing the portal is safe. Partial success (diagrams only or incomplete translation): A portal opens but is unstable. Crossing it deals 2d6 negative energy damage (no save). The sequence for the later rooms remains unknown. Complete failure / forced surge: All five portals flicker open for 1 round as swirling violet mist, then slam shut. Everyone in the room takes 2d6 negative energy damage (Fortitude DC 15 halves). The dial locks for 10 minutes and the party must take a longer route through the surrounding corridors.
Design notes
The goal is obvious: “The journal and the dial are clearly meant to be used together.” No single skill is mandatory. Language magic, Decipher Script, mechanical skill, or careful trial-and-error all work. Failure never hard-stops the adventure; it only makes the next linked portal rooms more dangerous or costly. The Undercommon journal reinforces that an illithid once operated this device inside the dwarven city, tying the alien technology to the fallen stronghold without needing any living (or undead) NPCs.