Rise of Tiamat - Episode X - Snipper Strikes

Roscoe rejoins the party and attempts to open the tower door, and succeeds. Inside, devils assail them from all around. The party defeats them, although Dain falls. The party ascends the tower.  Finally, they encounter Lord Diamond and Sorrowswallow. Oloril attempts to place Sorrowswallow in the bag of holding, but it releases psychic damage knocking all but Mullyn to the ground.

In a last great effort, the party captures Lord Diamond and takes the talkative Sorrowswallow. Once the party escapes with both, they meet Nulara and Lord Valmlor.   The cauldron is given to Lord Valmor and Nulara, as an envoy for the demon lord, makes contact with the council on their behalf.

Mullyn receives a message to go to Baldur's Gate. They are to test the town's resoluteness against the cult, and then proceed to the Misty Forrest and the report back. They also discover that Dain's soul is bound to the Underdark.

They arrive in Baldur's Gate and resurrect Dain. Lord Diamond is turned in to the authorities, and the party sets up a meeting with the Council. At the meeting, Rivatra, a known adventurer, reaffirms the town's dedication to destroying the cult. During the speech, many council members are assassinated by the infamous Snipper - who also severely injures Mullyn. Oddly, he seems to recognize Mullyn. After doing his damage, he disappears from sight . . .

Rise of Tiamat - Episode IX - Into the Keep

Off the party intends  to confront Lord Diamond in Eriabor. They teleport to Greenest with plans to walk the rest of the way. They land 100 miles away . . . The next day, they teleport successfully to Greenest. On horseback, they head to Eriabor. After arrival, Mullyn and Killian investigate the town to determine the location of Lord Diamond and the Cauldron. They determine his location, and discover that Diamond has not been seen for days.

At night, the party sneaks behind the keep. Upon crossing the fence, an alarm sounds and the party begins to fall  . . . upwards. Mullyn flies stopping his fall. The rest of the party continues their rapid ascent. Eventually, they begin to fall to the ground. At the last minute, Mullyn teleports them to (relative) safety.

Nights later, they fly across and land on the castle balcony. Inside the castle, they are attacked by guards. Quick work is made of the defenders, and the party proceeds to the basement. The enemies there are obliterated.

The next target our heroes choose is a nearby tower.