Highlights from the Sixth Episode of Season 2 of Under The Dome

When Barbie and Sam set out to investigate a mysterious tunnel, a cave-in severs their path back to Chester's Mill. Meanwhile, Julia and Big Jim face off in a struggle for power as a dust storm rages in the town, on UNDER THE DOME Pictured Mike Vogel as Dale "Barbie" Barbara Photo: Brownie Harris/CBS2014 CBS Broadcasting Inc. All Rights Reserved.

When Barbie and Sam set out to investigate a mysterious tunnel, a cave-in severs their path back to Chester's Mill. Meanwhile, Julia and Big Jim face off in a struggle for power as a dust storm rages in the town, on UNDER THE DOME. Pictured (L-R)Mackenzie Lintz as Norrie Calvert-Hill and Colin Ford as Joe McAlister Photo: Brownie Harris/CBS2014 CBS Broadcasting Inc. All Rights Reserved.

When Barbie and Sam set out to investigate a mysterious tunnel, a cave-in severs their path back to Chester's Mill. Meanwhile, Julia and Big Jim face off in a struggle for power as a dust storm rages in the town, on UNDER THE DOME. Pictured (L-R)Grace Victoria Cox as Melanie Cross, Mackenzie Lintz as Norrie Calvert-Hill Colin Ford as Joe McAlister and Alexander Koch as Junior Rennie Photo: Brownie Harris/CBS2014 CBS Broadcasting Inc. All Rights Reserved.

When Barbie and Sam set out to investigate a mysterious tunnel, a cave-in severs their path back to Chester's Mill. Meanwhile, Julia and Big Jim face off in a struggle for power as a dust storm rages in the town.

When Barbie and Sam set out to investigate a mysterious tunnel, a cave-in severs their path back to Chester's Mill. Meanwhile, Julia and Big Jim face off in a struggle for power as a dust storm rages in the town, on UNDER THE DOME. Pictured Grace Victoria Cox as Melanie Cross.

When Barbie and Sam set out to investigate a mysterious tunnel, a cave-in severs their path back to Chester's Mill. Meanwhile, Julia and Big Jim face off in a struggle for power as a dust storm rages in the town, on UNDER THE DOME. Pictured Grace Victoria Cox as Melanie Cross.