A lonely tower juts from the surface of a frozen lake, its tall conical roof a silent sentinel in the arctic waste. But the true scale of this monolith lies beneath the ice. Tower in the Ice is a masterclass in underwater environmental hazard design for 9th-level characters. Originally written by Skip Williams, this 12-page D&D 3.5 module challenges high-level parties to manage resource depletion, frigid temperatures, and a multi-level vertical assault against a cabal of fiendish hags.
Introduction: The Submerged Monolith
Set in a cold wilderness, the adventure centers on a structure built by an evil ogre mage centuries ago. After a geological upheaval, the tower was submerged, leaving only the top floor accessible from the frozen surface. Today, it is the lair of a “loathsome trio”: Puennoki (a half-fiend green hag), Chirkka (a half-fiend annis hag), and Hoinnia (a tiefling rogue).
The hook is deceptively simple: nomadic tribes are being terrorized by “three weird sisters,” or perhaps a wealthy scholar has hired the PCs to deliver a rare bird specimen to the tower’s resident “ornithologist.” Regardless of the entry point, the party will soon find that the hags’ hospitality is as cold as the lake surrounding them.
Narrative Core: The Hag Covey’s Ambition
The primary antagonists are on a quest to form a true hag covey. They have established a reign of terror over local nomads, exacting tribute in meat and ivory. The dynamic between the three is one of shared malice and tactical cooperation. They aren’t just squatters; they have modified the tower with unique features, like the leather air dome (Area 13) and a macabre frozen bird gallery (Area 7), reflecting Puennoki’s twisted obsession with avian life.
Tactical Breakdown: Five Levels of Frigid Peril
The tower is uniquely structured as a vertical climb—or rather, a vertical descent—into darkness.
1. Level One: The Above-Ice Guardpost
The only dry level, this floor is the party’s introduction to the tower’s occupants.
- The Sentry: Hoinnia (Tiefling Rogue 7) often greets visitors here. She is a master of deception, posing as a harmless servant to lure players into a false sense of security while two Ettin guards wait in the wings.
- The Atmosphere: A sulfurous haze from a coal brazier fills the rooms, contrasting with the biting cold outside.
2. Levels Two & Three: The Submerged Barracks
As the party descends the spiral stairs, they enter the flooded zones.
- Environmental Hazard: Characters take 1d6 cold damage per 10 minutes simply by being in the water. This creates an immediate “ticking clock” for the session.
- The Fiendish Merrows: These aren’t standard merrows. These are Fiendish Merrow Warriors with Smite Good and Spell Resistance. They use the water’s three-dimensional space to attack from above and below with longspears.
3. Level Four: Chirkka’s Sanctuary
The half-fiend annis hag, Chirkka, resides here.
- The Air Bubble: A massive oiled-leather dome (Area 13) creates a dry sanctuary. If the PCs slash this dome, it releases a hurricane-force wind that can blow Small or Medium characters right out of the room’s arrow slits.
4. Level Five: The Entry and the Floodgate
The lowest level features bronze double doors that act as the tower’s true entrance from the lakebed.
- Hydraulic Pressure: Because Level 5 is air-filled (via the bubble in Area 13), the water pressure outside is immense. Breaking these doors results in a catastrophic rush of water dealing 6d6 damage and potentially dragging PCs out into the deep lake.
The Boss: Puennoki (EL 8)
Puennoki is a Half-Fiend Green Hag and a tactical nightmare.
- The Tactics: She is a “pre-buffer” who uses Invisibility, Nondetection, and Unholy Blight.
- Weakness Attack: Her most dangerous tool is her special touch attack, which deals 2d4 Strength damage. For a party already struggling with the movement penalties of water, this can be a session-ender.
Mechanics & Hazards: Frigid Water Combat
Skip Williams utilizes the 3.5 underwater rules to their full extent:
- Buoyancy: Buoyant characters gain a +8 bonus on Climb checks, a rare helpful environmental factor.
- Weighting Down: The module provides a specific table for how much weight a character needs to carry to walk on the floor (e.g., 16 lbs for a Medium creature).
- Visibility: Even invisible creatures are detectable by the bubbles they leave behind, though they still retain a 20% miss chance.
System Conversion: 3.5 to 5e and OSR
The high-level nature of this module requires some careful stat-swapping.
For 5th Edition (5e):
- The Hags: Use the Annis Hag and Green Hag blocks from Volo’s Guide to Monsters, but add the Half-Fiend template (resistance to cold/fire/lightning, poison immunity, and wings).
- Cold Damage: Use the Extreme Cold rules from the DMG, adding an extra d6 of damage for immersion in frigid water.
- Ettins: The standard Ettin works perfectly for Level 1.
For OSR (Shadowdark/Old School Essentials):
- The Strength drain from Puennoki should be temporary (returning after a Long Rest) to avoid permanent character death in more lethal systems.
GM Tips: Selling the Verticality
- Sound in Water: Remind players that sound carries incredibly well through stone and water. Combat on Level 2 will alert the hags on Level 4.
- The Frozen Trophy Gallery: Describe the Gallery (Area 7) vividly. Hundreds of birds frozen in ice blocks like macabre balloons. It establishes Puennoki as a high-concept villain, not just a random monster.
- The “Wise Woman” Ruse: Let Hoinnia talk. If the players are willing to play along, let them meet the hags in their human disguises. The betrayal is much more impactful if they’ve shared a “warm” meal in a dry room first.
Conclusion: A High-Pressure Environment
Tower in the Ice is an excellent choice for GMs who want to move beyond the typical forest or dungeon setting. It forces 9th-level characters to solve logistical problems—how to breathe, how to stay warm, and how to fight in three dimensions—before they even face the hags. It is a dense, rewarding challenge that provides one of the best underwater experiences in the 3.5 library.
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