Sigmundur

Grunt tackles the science behind some of a soldier's most challenging adversaries - panic, exhaustion, heat, noise - and introduces us to the scientists who seek to conquer them. Mary Roach dodges hostile fire with the U.S. Marine Corps Paintball Team as part of a study on hearing loss and survivability in combat. She visits the fashion design studio of U.S. Army Natick Labs and learns why a zipper is a problem for a sniper.

1982: Oregon businessman Phil Champagne, age 52, dies in a tragic boating accident off Lopez Island. He is survived by one ex-wife, four adult children, an octogenarian mother, and two despondent brothers. Phil didn't know he was dead until he read it in the paper. All things considered, he took it rather well. So did Phil's brother, Mitch, the beneficiary of a 1.5 million dollar policy on Phil's life.

Terrorism expert Erick Stakelbeck pulls back the curtain on ISIS, the violent terrorist organization spreading death and hate in the Middle East. The rise of ISIS took the White House by complete surprise: President Obama called the group "JV" then was forced to reassess when ISIS began executing innocent American journalists. Now radicalized Americans and Europeans are joining ISIS' ranks.