Beaten down after weeks in the Alaskan backcountry, the competitors brace for one last battle involving treacherous glaciers, volatile rivers and perilous mountains. Dropped in a glacial river valley, the four teams charge toward the final insertion flag, where they find a cache of mountain bikes. As the defending champions, Dallas and the Endurance team are eager to bring home two titles in a row. But when Ben takes a nasty fall, the fierce competitors gamble on a shortcut through a glacial crevasse to try and get back in the running. Against all odds, Lower 48 enter the final leg with a chance to win it all. But when Cluck slips into a crevasse, it’s up to Kasha to pull out her partner, or risk losing him … and the competition. The Alaskans enter the final leg with a shot to tie Endurance with a win. Stranded on the top of a sheer cliff face, the men must dig deep and improvise a route to the finish. For the Military, this final leg is about more than a title — it’s about revenge. After narrowly losing to their Endurance rivals last year, the team has set their sights on beating Dallas all season. But after weeks of suffering in the wild, will they have the energy to outmatch the athleticism of Endurance?