Third Street Girls is a cancelled sequel to The Sinister Three.
- Following from The Sinister Three, an assassin named Cypher teams up with Shaundi and Viola in order to bring down the Sinister Three's operations and try and make contact with the 3rd Street Saints.
- Cypher, Shaundi and Viola will be the three playable protagonists.
- Sentient Jack and Kinzie attempt to redeem themselves by defecting from the Sinister Three when things get out of control. However upon their usefulness being carried out, there will be a choice whether to spare them or not.
- The setting is "Sinister-port" which is basically just Steelport with slight modifications and a more nightmarish look (similar the the simulated version in Saints Row IV).
- Mr. Sinister is the main antagonist. He will also have a second in command (yet to be named).
- Characters from "Snatch a ho" will return with a slightly bigger role and can be recruited.
- In an activity similar to snatch, either Shaundi, Viola or Cypher can steal back prostitutes working for the Sinister Three in order to free them.
- A mission similar to "The Ho Boat" from Saints Row: The Third will see the Third Street Girls save the "hos" before they are taken away from Sinister-port.
- Viola DeWynter
- Mr. Sinister
- Sentient Jack
- Kinzie Kensington
- Vanessa Robertson
Although early days, Mr. Johnson has stated he would be interested in a follow up story and making it a trilogy. Other spin-offs maybe in the works in order to expand the "Sinister-verse". A planned story is a crossover with the yet to be released Gat Out of Hell which will possibly depict Mr. Sinister in Hell trying to strike a deal with Satan.