The promo picks up right where last season left off, with Barbie atop a gallows with a noose about his neck.
Creator Brian K. Vaughan hinted one or more characters may die in the sophomore season … could Barbie be one of them?
"No one is safe in this town," Vaughan said.
In other scenes from the clip, residents of the town appear to be dragged by an unseen force before collapsing. Only Big Jim seems to be impervious to the force.
"Tell me what to do. Tell me!" Big Jim yells out.
Under the Dome returns to the small screen at 10 p.m. EST June 30.