Last season, Marvel‘s first series for ABC, Marvel’s Agents Of S.H.I.E.L.D., sailed through development to the schedule surrounded in secrecy. The company’s new ABC effort, Agent Carter, is taking the same route. While it has never been officially announced, the project already has a finished script awaiting green light, and “the script is great,” ABC’s Paul Lee said at TCA this morning. Like with S.H.I.E.L.D. — from Joss Whedon, the man behind Marvel’s blockbuster The Avengers that featured the S.H.I.E.L.D. organization — Agent Carter too was written by writers of the Marvel tenpole that spawned the TV project: Captain America: The First Avenger‘s Christopher Markus and Stephen McFeely. Inspired by a Marvel one shot, Agent Carter brings back Captain America’s girlfriend Peggy Carter, played in the movie by Hayley Atwell. The period drama chronicles her life as a budding secret agent after her boyfriend is stranded in ice. As we reported, Reaper creators Tara Butters and Michele Fazekas are shepherding the project as executive producers/showrunners. “She is such a strong character,” Butters said of Peggy. “I think this is a great premise that would make a great series.” In other Marvel-ABC TCA news, Lee announced that a Thor character, Lady Sif, played by Jaimie Alexander, will make an appearance on Agents Of S.H.I.E.L.D. later this season.