When Lightman investigates a coal mine explosion that killed six miners, he suspects that foul play may have been involved. To find the truth, he puts his life at risk and descends below the surface. Meanwhile, the FBI comes back to The Lightman Group looking for help with another case, and Foster and Torres offer to work pro bono.

Cast: Tim Roth, Kelli Williams, Monica Raymund, Brendan Hines, Ronnie Gene Blevins, Lindsey Kraft, Jennifer Marsala, Jack McGee, Ivo Nandi, Justin Reed, Christopher Thornton