A murder may have occurred aboard Snowpiercer but according to Melanie Cavill (Jennifer Connelly), things are well under control. In a sneak peek at Sunday's episode of the TNT series, the woman tasked with delivering announcements over the PA system, aka the Voice of the Train, tries her best to quell first-class passengers' concerns over the open investigation and a growing rebellion among the lower class. 

"I think a rebellion is overstating it," Melanie says in the preview, attempting to reassure the upper-class passengers that everything is fine. But with six dead after a clash between the lower-class passengers and the authoritative figures trying to maintain order, things are far from OK. 

The Best Shows and Movies to Watch This Week: Homecoming Season 2, The Lovebirds

The episode, titled "Prepare to Brace," finds Layton (Daveed Diggs) using his new position as train detective to investigate the murder while also secretly gathering intel for the revolution. Meanwhile, Melanie will have her hands full with not only keeping first-class passengers calm but also dealing with an impending resources crisis that could lead to disastrous consequences for everyone on the train. 

Snowpiercer airs Sundays at 8/7c on TNT.

Jennifer Connelly, <em>Snowpiercer</em>Jennifer Connelly, Snowpiercer