We celebrated the 3rd anniversary of our campaign, currently at 87 sessions, with the player characters reaching 14th level. They earned enough XP from the last adventure that they're actually on the cusp of 15th level. It's the longest lasting campaign I've run by a significant margin.
It was an entire session of roleplaying and debate among the players as to their next steps. The characters are close to defeating the Zhentarim, Manshoon, and his army of clones. However, Manshoon still has a few tricks up his sleeve. This gets complicated, so buckle up.
First, Manshoon approached the halfling bard with a proposal. The bard was alone, having teleported to Waterdeep hoping to find a safe spot for the Orb of Dragonkind the party had recently obtained. He discovered that Waterdeep had been conquered by frost giants under the secret direction of Manshoon. Also, the bard's brother has now been installed as Open Lord of Waterdeep -- again, with the hidden aid of Manshoon.
Unknown to the rest of the party, the bard's soul is actually trapped in Hell, and his body is currently occupied by an agent of Glasya, daughter of Asmodeus. Manshoon knows all of this and wants to make the bard his ally. Manshoon tells the bard that he knows it's only a matter of time before the frost giants are defeated and Waterdeep liberated. He wants the bard to defeat his brother and become Open Lord. Manshoon will betray his allies and help the party. In return, he wants the bard to secretly advance the Zhentarim's agenda once he becomes Open Lord.
The bard says he'll think it over...
Second, the party's tiefling sorcerer is the offspring of a union between Manshoon and Glasya. Manshoon visits the sorcerer in a vision. He tells her that at this very moment, he has conquered Blackstaff Tower, captured Vajra Safahr, and is commencing a ritual to transfer his soul into the Blackstaff. He wants the sorcerer to lead the party to Blackstaff Tower and defeat his minions. Then he wants her to kill him. Unknown to anyone but the two of them, his soul will live on in the Blackstaff. By day, the sorcerer will be the mistress of Blackstaff Tower. By night, she will lead the Zhentarim. Together, they will rule the North as father and daughter.
The sorcerer says she'll think it over...
I had roleplayed this in full view of all the players. While I'm trying to turn the characters against each other, I don't want to turn the players against each other. There are pros and cons to playing my hand with all the cards facing up. We'll see how it goes.
The rest of the session was the players debating what to do about all of the above.