Maze of Peril Ch 1, Scene 5: "The Ancients Worked on a Grand Scale"

This post is part of the Tales of Peril Book Club, indexed here.

Boinger and company now prepare to descend the staircase into the dungeon. They leave their horses behind, hobbled, but bring the mule with them. This is in line with the Basic rulebook: "Mules can often be taken into dungeons and they can carry 3,500 gold pieces. Horses can usually carry more, but lack the ability and calm necessary for dungeon expeditions", which is in turn adapted from OD&D Vol 2, "Only mules are agile enough to be taken in dungeons".

The marching order is specified, very much like a D&D party entering a dungeon. The "advance party" has a front rank of Zereth, with lit torch, and Olaf, and Haldor behind them with a second torch. Following are Murray, Bardan and finally Boinger leading the mule. The mule has shod feet that make loud "clomp-clomp" noises in the dungeon.

They descend straight down the ancient stone stair to a passageway of roughly cut stone blocks. Compare with Sample Dungeon in the Basic Rulebook: "The stairway from the surface leads twenty-five feet straight down and ends in the corridor marked START on the Dungeon Master's map."

The east-west corridor is immense, 25' high and 25' wide, leading Boinger to comment that the "ancients worked on a grand scale". Murray is less impressed, replying "this is nothing...The dungeons are endless. Some of the old books say they extend to the heart of the earth". Murray's comment indicates he is familiar with the description of the Underworld given earlier in the chapter. While the Sample Dungeon in the Basic Rulebook has standard-sized corridors (10' wide, 10' high), some of the rooms are similarly large scaled. 
Room A, for example, is 120 by 100 feet in size.

They unexpectedly find that the floor of the corridor is coated in "a trail of opalescent grey slime". Opalescent is an obscure word meaning that something shows "a glimmer of different colors when rotated or seen in different angles" (per minerals.net). I imagine the slime trail is illuminated in this manner as the party moves its torches about.

"Opal displaying Opalescence", from minerals.net

Zereth identifies the slime as coming from a "Worm", and that it is "nearly dry. Made hours ago", suggesting some familiarity with this. The others don't question this, so they must have at least heard of what he is referring to. They then refer to it as a "creature", and worry about it encountering it, giving the sense that it is a large creature. If you are familiar with D&D, you'll certainly suspect that they are talking about a Purple Worm, although Holmes has added the detail about the slime, perhaps based on the trails of snails and slugs or simply the sliminess of earthworms.

The party debates over whether to head east or west, worrying about whether they will come up behind the monster if they go west, or have the entrance cut off if they go east.
Zereth scouts each direction in the dark using his infravision. Bardan says he thinks that Zereth can see better than him in the dark, though in D&D they both have infravision to 60'.

When Zereth returns, his eyes reflect green in the torchlight, suggesting a tapetum lucidum like found in many animals, for example cats, giving improved night vision. Holmes researched neurobiology using cats as a model animal, for example see this abstract.

Zereth reports a cross corridor 70' in either direction. While Boinger has a snack (a recurring theme), Bardan and Zereth decide to head east, based on Bardan sensing more corridors in that direction. Per the Basic Rulebook (and OD&D), dwarves are attuned to underground construction, being able to "detect slanting passages, traps, shifting walls and new construction about one-third of the time" (i.e., 1-2 in 6).

In the next scene we'll see what they find when head east down the dark corridor.

Descriptions:

Murray: Long robe, conical hat - again this is in line with the standard D&D wizard as seen on the cover of the Basic rulebook.