Having found the Letter from Drake Morgrave , which revealed the plans of the Emerald Claw agents, Arc decided to attack. Using Minor Illusion to draw some of the terrorists to one particular spot of the wooden platform attached in the trees; then, the former Karrnathi agent unleashed a Fireball, severely burning the targets, while setting the platform on fire. The party then set about taking care of the Emerald Claw forces; Elias Minch ran up a tree and engaged in hand-to-hand, while Daellin and Smith sniped from the ground.
The head of the Emerald Claw contingent, the dragonborn warlock, used Scorching Ray to pulverise both Arc and Elias Minch. Arc responded by trapping the warlock in a hemispherical dome Wall of Force, which prevented the dragonborn from casting a spell, and trapped in him in position as the hanging bridge that he was stood on caught fire. The bridge gave way, causing the warlock to topple to the ground (as Arc hurt him with words simultaneously). The party, having taken care of the rest of the Emerald Claw, converged on the crippled leader. He was able to let off one last spell, a Wall of Fire that dropped Arc to unconsciousness, before Daellin was able to finish him off with an arrow to the throat.
The party healed Arc, and decided to use some healing potions that they found to recuperate. They elected not to rest, but instead to press on after the rest of the Emerald Claw agents, that were headed up Widow's Peak to the location where the Brelish soldiers had hidden the lich's phylactery. The climb was laborious but not difficult; after several hours of climbing, they had got high enough that there was snow on the ground, which meant following the path left by the Emerald Claw agents was not difficult. They caught sight of a ruined temple ahead of them; the peace of the climb was interrupted by a loud crack, and strange arcane energy could be seen surrounded in the temple. As they got closer, they climbed over a ridge to hear screams; in front of them they could see the remaining Emerald Claw agents, each connected to the temple by an arcane tendril. Their puppet-like movements showed that they were all dead, and being controlled by something or someone.
The party tore threw the newly-turned zombies, and it was Elias Minch that got most of the kills with his Mace of Disruption. Trekking over an ice bridge that led to the temple, the party found the lich inside; sealed within a cocoon connected via the arcane tendrils that they had been seeing to the last two zombies. With those two despatched, the lich emerged and joined the fight. It quickly proved to be a brutal opponent; casting Blight to devastate the party, and using the same arcane tendrils that had been connected to the zombies to pass some of the wounds inflicted onto Smith instead. Arc's Polymorph spell failed twice, and Bigby's Hand was soon disrupted. Elias Minch found himself quickly taken out of the fight with an early Paralysis; he was forced to watch as the rest of the party struggled, with Daellin audibly calling for them to retreat. Smith went down, and while Arc stepped in to heal the warforged, Elias Minch broke free and stunned the lich, which let Smith come in with his cannon for the final blow, as the lich was consumed in fire.
The party sealed the phylactery back up in the box that it had originally been found in, and returned to Euryale, who thanked them for their help. With that, the quartet returned to Sharn, their adventures together finally concluded.