ABC has released a teaser for the second season of “Marvel’s Agents of SHIELD,” providing a sneak peak of the show’s cast as they enter a “make or break moment.”

After the events of the first season, which depicted many of the changes to the Marvel universe made in “Captain America: The Winter Soldier,” “Marvel’s Agents of SHIELD” took a darker turn. Agent Phil Coulson (Clark Gregg) narrates the trailer, stating that the titular team must now “live in the shadows, to protect the innocent, to save lives.”

The superhero show, which regularly ties in events from Marvel’s theatrical releases, has picked up many new cast members for its second season, including Lucy Lawless as Isabelle Hartley, Nick Blood as Lance Hunter and Adrianne Palicki as Mockingbird. The show will also take a mid-season break in winter, leaving time for the premiere of spinoff “Agent Carter.”

“Marvel’s Agents of SHIELD” will premiere at 9 p.m. Sept. 23 on ABC.