Near a remote fishing town named Warrenhome, there is a crumbling monument 300 feet from the shore. A stone slab awaits there…
Level-4 Adventure
For two centuries, the townsfolk of Warrenhome have shunned this place they call ‘The Sea Tomb’. A dilapidated stone path leads into the breaking waves and to a roughly circular, artificial islet. No one alive has read the engraved stone slab that lies there. Apart from local superstition, the Sea Tomb is protected by a unique breed of territorial hexapi.
Inscription. In Draconic script, the slab says: “Begone, traveler, nothing but death awaits you. Be not a victim of your greed. Walk away and keep your life.”
The Truth. Centuries ago, a powerful mage became a lich. She hid her phylactery here. Later on, she moved away from the Material Plane. She magically created the guardian hexapi that protect the vault from outside.
Chimeras. The strange mollusks that protect the islet are a chimeric merging of the common octopus and a type of mushroom.
Bound Hexapus
A marine critter with six tentacles that floats in the sea surface and shoots spore balls.
AC 13, HP 15, ATK 2 spore ball +2 (1d6 + goo), MV near, S -1, D +2, C +2, I +0, W +1, Ch +0, AL N, LV 3
Goo. Target is pushed to near by the spore goo. If the target hits a solid surface, DC 12 STR or adhere to it. DC 12 STR on turn to free from the adhesive.
Random Events – 1d6
| Details |
| 1. Four bound hexapi emerge from beneath the sea waves around area 2, seeking the characters. They go as far as jumping into the dungeon to reach them. The enraged mollusks cannot be reasoned with. |
| 2. Four brigands (toughs) from Warrenhome, encouraged by the characters’ willingness to visit the Sea Tomb, set out after the party. They are not sure yet whether to join the party or try to rob them (Reaction). |
| 3. Inside the dungeon, five mushroomfolk detach from a wall as part of their natural growth process. They are vulnerable due to their recent maturing and take double damage. They only attack in self-defense. |
| 4. An acolyte from the Sun Church in Warrenhome catches up with the characters. He was sent to warn the party not to breach the entrance in area 2. The local church believes the place is cursed and bathed in evil. |
| 5. If the entrance in area 2 is opened, the tide rises and causes water to pour into areas 3 and 4. The water in these chambers reaches a height of 4 feet. Fortunately, the water drains out after 1 crawling round. |
| 6. Terrible, cackling laughter can be heard from all directions. The lich’s voice then says: “After so long, you dare come into my abode? Leave at once or become the targets of my ire. You do not want to enrage me…” |

This adventuring supplement is designed for D&D5e. On our Patreon page you can get it in PDF format (see image). Notice that some of the layout elements can only be presented as intended in the PDF layout (side-margin boxes and statblocks). The downloads include hi-res images for the maps.
Adventure Hook
The characters rest in Warrenhome after completing a perilous quest. They soon hear rumors about a nearby place by the shore. The locals call it the Sea Tomb. No one has ever explored this place; the townsfolk have fun telling exaggerated stories about the place or theorizing about the strange riches and artifacts that must be hidden inside. Alas, this is all hearsay and speculation. The valiant characters, seeking glory, renown, and gold, have decided to check out the place. Since it has been abandoned for so long, there is a chance that treasure awaits within.
The Journey There
Leaving from Warrenhome’s east gate, the Sea Tomb is within a half-hour walk, following the shore. It can be seen from afar: a straight path that enters the sea, just above the sea waves. It leads to an islet. From a distance, only a threshold-like structure can be seen there.
1. The Broken Path
A straight, 300-foot-long path leads into the ocean to an islet. The cracked, stone flooring has seen better days. Some sections of the narrow path have crumbled away.
The walkway is barely above sea level during high tide. Still, there is ample evidence of water erosion in most stone flooring slabs.
Fauna. As the party walks toward area 2, octopus-like creatures gather near the area. They have six tentacles and fungus-like heads.
2. The Islet
An archway without a keystone precedes the slanted monument that the locals call the Sea Tomb. The slab is engraved with silver inlays.
In the old Draconic speech, the inscription reads: “Here lies death, pain, and misfortune.” If the slab is pushed aside (DC 12 STR check), a hole is revealed beneath. Area 3 is 85 feet below.
Attack. When the characters cross the threshold, five bound hexapi surface near the islet border and attack with their spore balls. The animals are magically conditioned to behave this way.
3. Fungal Garden
The air in this dark, damp chamber is suffused with spores and fungal vapors. Some of the mushroom caps that carpet the uneven cave floor produce a faint, natural luminescence.
Descent. With enough ropes, the characters can tie them to the arch in area 2 for the descent (DC 12 STR). Failure by 5 or more means the character falls midway and takes 3d6 damage.
Denizens. Two mushroomfolk and six violet fungi rise from the fungal carpet when the first character touches down. They attack mercilessly.
Secret Path. A large rock near the far wall covers an opening leading 50 feet down to area 4. Grime, mud, and fungus cover the rock, making it look fixed in place (DC 12 WIS to notice).
I leave my humanity and mortal lifespan behind. I am now superior to all I knew.
Wall Inscription
4. Room of False Doors
Four arched thresholds with metal, slidable doors are set side by side on the cavern wall. A handle on each door can be used to open it. Behind each door, there is a 5-foot-deep alcove. Two contain animated armors, one contains a stone golem (depicting an armored combatant), and the last one is seemingly empty. There is a secret door in the empty alcove that leads to area 5 (DC 12 WIS to find it). Casting the Detect Magic spell reveals the magical aura of the golem and a strong aura of necromancy coming from area 5.
5. Vault of the Phylactery
The narrow passageway leads to an ominous chamber. Atop a pedestal sits a glimmering quartz stone. Its purple glow bathes the room. Four skulls on narrow pedestals gaze at it.
The Skulls. A last line of defense to protect the lich’s phylactery, the skulls are enchanted with magical runes. The two skulls next to the entrance cast Acid Arrow at the first creature that enters the room. The skull left of the phylactery casts Hold Person on a random character. The last skull casts Lightning Bolt, presumably targeting all creatures in the incoming passageway.
The Phylactery. The quartz stone is the source of the necromancy aura detected in area 4. This artifact is The Phylactery, a receptacle that contains a part of the lich’s life-force. It was hidden here to safeguard her life. If a character touches it and Random Event 6 has not yet occurred, it happens now. The malevolent lich is aware of the characters’ intrusion into her secret vault. Either an adamantine or a +2 weapon is needed to destroy The Phylactery. On the other hand, the characters can keep it and benefit from its power.
Conclusion
If they keep it, the heroes have gained a powerful artifact and earned the enmity of a lich. Fortunately for them, the lich is far away and shall not come soon. But she will, sooner or later. The characters can leave The Phylactery alone or try to destroy it. What will happen next, only time can tell.
The Phylactery
A gleaming, uncut piece of quartz
Benefit. Gain a +2 bonus to spellcasting checks made for spells that cause damage.
Curse. The lich knows you, where you are, and can always read your surface thoughts.

This awesome cartography piece was featured in on our Patreon page and on issue 72 of Dungeon Vault Magazine.



