As the Race to the Center of the Earth heats up, teams are pushed to the limits of both mind and body. In Canada, a snowstorm puts the team in a bind. In Vietnam, one adventurer will have to face her fears. In South America, the fabric of the team will be tested. And in Russia, the team endures the longest day of the course.

The race continues, and for each team it will take physical and mental strength to endure. In Russia, car troubles jeopardize the team's lead in the competition. In Canada, relationships are put to the test. In South America, the team must make a risky decision. And Team Southeast Asia will face their most exhausting challenge yet.

The Race to the Center of the Earth hits the halfway point, the Big Reveal brings new information to the teams. Competition revs up as teams are faced with harrowing challenges while emotions run high. Teams are gunning to steal first place, but do they have what it takes to win the million-dollar prize?