# Scene 1 – The Nursery ### Boxed Read Aloud > The tunnel opens into an immense cavern. Thick organic roots descend from the ceiling into several enormous pools of dark, still liquid. Within each pool, pale tadpole-like creatures drift lazily through the water, occasionally disappearing beneath the surface before emerging elsewhere. Around the chamber, rows of living platforms support restrained prisoners connected to the walls by fleshy tendrils. Some struggle weakly. Others remain motionless. Hooded thralls move methodically between them while grimlock guards patrol elevated walkways overlooking the chamber. > > Every few moments the walls pulse with another slow heartbeat. Each pulse causes the prisoners to shudder as though something unseen has reached into their minds. --- ## What the Players Notice - Prisoners awaiting ceremorphosis. - Tadpole incubation pools. - Thralls preparing captives. - Grimlocks guarding the chamber. - A massive tunnel of intertwined nerves leading deeper into the hive. --- ## Investigation |Check|DC|Information| |---|---|---| |Investigation|13|The prisoners are scheduled for ceremorphosis within hours.| |Medicine|14|Several captives can still be rescued.| |Arcana|15|Psychic energy constantly flows from the tunnel beyond into every part of the Nursery.| |Nature|15|The entire chamber depends upon living tissue connected to the hive's central nervous system.| --- ## Player Choice The party must decide how to proceed. - Attempt to rescue prisoners before being discovered. - Ignore the captives and move directly toward the Elder Brain. - Sabotage the Nursery before leaving. Each choice has consequences. Rescuing prisoners creates distractions during the coming battle but risks alerting the defenders sooner. Ignoring them allows the party to advance more quickly but leaves innocent captives behind. --- # Scene 2 – Battle in the Nursery The moment the defenders recognise intruders, the chamber erupts into chaos. This is the largest combat encounter in the adventure. - 3 Mind Flayers - 4 Thralls - 2 Intellect Devourers The Mind Flayers coordinates the defence while remaining above the battlefield. Thralls trying to grapple the adventurers. The Intellect Devourers remain hidden until vulnerable targets expose themselves. --- ## Terrain Features The battlefield should reward movement and tactical positioning. Incubation pools count as difficult terrain. Any creature beginning its turn within a pool must succeed on a **DC 14 Constitution saving throw** or take **2d6 psychic damage** as immature tadpoles swarm around it. Suspended incubation pods may be destroyed. A falling pod crashes into the area beneath it, forcing creatures within 10 feet to make a **DC 14 Dexterity saving throw** or suffer **2d8 bludgeoning damage** and fall prone. Large nutrient veins crossing the chamber can also be attacked. Destroying one causes it to rupture violently, spraying organic fluid and causing a 15-foot section of floor to become difficult terrain until the end of the encounter. --- ## Outcome When the Mindwitness dies, the defenders lose much of their coordination. During the final rounds of combat, every creature in the chamber suddenly pauses as an overwhelming psychic command echoes throughout the hive. > _"Protect the Brain."_ The remaining defenders immediately withdraw toward the tunnel instead of continuing the battle. The path to the Elder Brain is now open. --- # Scene 3 – The Neural Conduit The passage beyond the Nursery resembles an enormous living nerve running through the centre of the hive. Every surface pulses with psychic energy, and faint memories flicker across translucent membranes lining the walls. As the party advances, each character hears fragmented thoughts within their own mind. They experience brief flashes of the Elder Brain directing every patrol, every prisoner transfer, and every defence throughout the colony. A successful **DC 14 Arcana** or **DC 14 Investigation** check confirms what has only been suspected until now. The Elder Brain is not simply the colony's leader. It is the mind through which every illithid within the hive acts. Destroying it will sever the psychic network that binds the colony together. --- ### SECRET PUZZLE Run the puzzle to open door to Elder Brain # Scene 4 – The Elder Brain ### Boxed Read Aloud > The tunnel widens into an immense circular chamber. At its centre lies a vast pool filled with glowing violet fluid. Suspended above the surface is an enormous exposed brain, its folds wrapped in countless pulsing veins that disappear into every wall of the chamber. Every heartbeat sends ripples across the liquid below, while arcs of violet psychic energy leap between the Brain and two silent figures standing upon opposite platforms. > Both mind flayers turn as one. > > Without speaking, a single thought presses into every mind. > **"You should never have come here."** --- ## Final Encounter Enemies: - Elder Brain - 2 Mind Flayers --- ## Battlefield Features The chamber contains four towering nerve pillars supporting the psychic network. Each pillar has: - AC 13 - 20 hit points - Immunity to psychic damage Destroying a pillar weakens the Elder Brain's connection to the hive. For every pillar destroyed: - The Elder Brain loses one Legendary Resistance (if using them). - Its psychic pulse deals 2 fewer damage. - Psychic communication throughout the chamber becomes unstable. Characters willing to spend actions attacking the environment can therefore make the final battle significantly easier. --- # Conclusion The moment the Elder Brain dies, an overwhelming psychic scream reverberates through every chamber of the hive. The two surviving mind flayers stagger, clutching their heads as the connection sustaining them vanishes. Throughout the colony, thralls collapse, grimlocks flee in confusion, and the living walls begin to convulse uncontrollably. Veins rupture, chambers collapse, and the organic structure that sustained the hive starts to die. The adventurers have only moments to escape. As they flee through the collapsing tunnels, they pass freed prisoners and disoriented thralls struggling to comprehend what has happened. Reaching the surface, they witness the surviving mind flayers abandoning the colony. Without the Elder Brain to coordinate them, the invasion has failed, and the remaining illithids retreat into the depths rather than continue a battle they can no longer win. The colony is destroyed. The prisoners are free. For now, the region has been spared from becoming the birthplace of a new illithid empire.