With the defeat of the immolith, the children of light felt its demonic influence disappear from the realm. They rested overnight before travelling to face the other power they had sensed. The group arrived at a wide cave mouth facing a tree-lined pond. A slightly raised pathway split the stagnant water and led to the opening. Aten noticed that the hollow had been dug out by a large creature, while Glace spotted several humanoid skeletons in the murky pond and various tracks on the muddy banks. He pointed these out to Demarung, who examined the imprints and discerned boot marks as well as the prints of a large draconic creature and two odd tracks he could not identify – a smaller set of clawed tracks and a large set of bulbous prints. The party also noticed clumps of green residue on some of the nearby mangrove trees and in one of the tracks.
Alec and Glace began to move slowly toward the cave mouth, investigating the path as they went. As they neared the opening, a blob of green slime rose from the ground near Glace, revealing eyes and a mouth as it crawled forward to attack. A four-headed hydra, its scaly armor enhanced with metallic plates, appeared in the cave entrance a moment later and issued a challenging roar. Glace reacted by smashing the green creature threatening him before teleporting to engage the hydra. He lashed at the beast with his flail, striking it with a divine blow that hurtled the avenger and his foe away from the cave mouth. Three more of the viscous green creatures appeared and attacked. The first dropped from a mangrove and burned Demarung with a blast of acidic slime, while another crawled out of a deep footprint in the mud and spewed its caustic muck on Aria. A third emerged from the cave and charged Glace, but he dodged the corrosive attack. Aria smote the green creature threatening her, and the warden slew his foe before moving forward to face the hydra. Alec cursed the monster and assaulted it with a spell at it as he stepped back, but one of the beast's heads lashed out and bit him as he moved away. Demarung and Glace both struck at the distracted hydra as the warlock teleported to a safe distance. Aten charged into battle and breathed his draconic fire on the beast while Ember summoned a column of divine fire that burned one of the hydra's heads to ash.
The beast moved to pursue Alec, and the party watched in shock as two new heads grew from the charred stump to replace the one that had been destroyed. The hydra's five heads lashed out at the warlock with a flurry of bites. Alec felt the hydra's fangs bite deeply several times, suffering severe wounds that bled profusely. Glace attacked the monster's flank and struck with divine menace that weakened his foes' resolve, making them easier to hit. Meanwhile, Aria used arcane power to heal some of Alec's wounds and chanted a hymn that allowed the warlock to teleport to her side. She then sang a dissonant strain that assailed the hydra's psyche and fouled its attacks. Demarung aided Alec by calling on the primal power of earth to move the warlock to safety and protect him with a barrier of stone. The warden then turned back to his foe and surged into a frenzy, slashing the hydra with his sword. Alec, now safely out of the monster's reach, slammed his fists together and conjured a circle of darkness around the hydra that assailed its mind and crushed its will. Aten circled the beast, trying to draw its attention as Ember used her divine power to heal more of Alec's wounds. The hydra, enraged, unleashed another barrage of attacks at several of the children of light; Demarung and Ember were both bitten by multiple heads but Aria managed to dodge two that bit at her. As the beast regrouped, Glace teleported to face it and unleashed a barrage of his own. The first strike of his icy flail froze and shattered one of the monster's heads, but two more sprouted from the neck. The avenger destroyed both of these as well, hammering each with a frigid, crushing blow, and the hydra fell. Seeing all of its allies defeated, the remaining green slime-creature turned and fled into the cavern. Alec cast a wrenching curse after it, and the party heard its dying scream echo from the cave mouth.
The children of light examined the corpses of their vanquished enemies. Ember recalled vague memories of the strange green creatures. They were the spawn of pod-demons. These demons possessed a madness born of the Seed of Chaos, and their insanity animated the green spawn they left in their wake. The group focused their will on forming their surroundings but still sensed two forces in opposition – the beacon created by Io, and an elemental will within the cave. As the party rested and tended to their wounds, Glace and Alec stealthily explored the cave. They spied a flickering red light leading down long, winding tunnel that descended into the hillside. Following it, the two found a large cavern with tiers formed from the rock around the far edges. On the other side of the cave stood a portal made of jagged, black stones; red flame licked the air on the other side of the arcane doorway, casting dim, scarlet light into the room. Two red toad-like demons known as slaad flanked the portal, guarding the entrance. A trail of green slime lead up into the hidden recesses of the highest tier, and the two adventurers could hear the chittering of unknown creatures issuing from the darkness. Glace and Alec slowly and silently retreated to share what they had seen with their companions.