Military action
After an attempted assassination by the Thieve's Guild, the Solitar Souls decided to go after them to end the threat they posed, with the help of Darkie and Carter.
It is generally not a good idea to assassinate someone that is well-loved. But what remained of the Thieve's Guild did not care, and had sent Carter and Darkie after Amaryllis, Riot, or both. Unfortunately, they underestimated Amaryllis' personal charisma, and saw Carter and Darkie switch sides.
With an idea of where to go and the assistance of Carter and Darkie to enter, the Solitar Souls were able to assault the hideout, leading to the deaths of most of the remaining members of the guild, sparing only one who was far too simple to have any malice and whom Darkie vouched for. Continuing on, the Solitar Souls found and attacked the guild leader -- "Tiny" Tina -- and killed her in short order.
Once complete, it was time to turn their attention to the Succubi who should have been there...