In the third round of the Battle of the Branches, four Marines are tasked with forging one of the most versatile, and iconic combat knives in history: the KA-BAR. As an additional challenge, these smiths must adapt and overcome to forge together metals from a massive anchor using the San Mai technique. After a punishing round of testing, the two surviving smiths return home to forge a weapon that was crucial to history: the Marine Corps Officers Sword. Only one Devil Dog can earn the right to stand at the Marine Anvil and compete for the $50,000 grand prize.