Very little about the new season of Marvel's Agents of SHIELD is known at this point. The series ended with the team having defeated Madam Hydra/Aida and then being taken by an unknown group only to find Phil Coulson (Clark Gregg) months later living on what looked to be a space ship or space station.
And we won't be getting many answers soon as SHIELD won't return until after Marvel's Inhumans has it's full 8-episode run starting this Friday night, September 29th. It is expected they will continue the story arc format they started with last season where it was broken into Ghost Rider, LMD and Framework.
A poster has been released for the new season with very little in it other than metal wall with the SHIELD logo emblazoned on it and a window looking out into space. The end of the season almost made it look like Coulson was a prisoner… but maybe there was a division of SHIELD set up on a satellite.
At Heroes & Villains Fanfest this month, Ming-Na Wen was a guest and all she'd say about the upcoming season was, "You will be very, very impressed [by the premiere]. There's a lot of action."
If the Inhumans run for eight-weeks straight, then they will wrap up the Friday before Thanksgiving, meaning ABC would likely skip holiday weekend and start SHIELD either sometime in December or wait until just after the new year. I can't see them firing the show up for a week or two in December only to go back on Winter hiatus. We might here more about the season and when the series will return at the NYCC next month.