Concept: "Explore the chaotic passages beneath Verhu's catacombs... occult relics and terrifying creatures lurk therein!" 
Content: A two-player expansion to Basilisk!, with chaotic tunnels to explore.
Writing: Rules additions, clarifications, and supplementary tables establish the interactions between the base game and Tunnels of Nechrubel.
Art/design: The same tasteful, textured, printable, clean layout as the original
Usability: Consistency in visual elements and subtle navigation aids in easy reference.