The Pawn Stars look to buy an American off-roading motorcycle classic--a 1967 Rokon Trailbreaker--but will this deal get stuck in the mud? Then, Rick is hesitant when a man brings in a rare mint condition 1715 Escudo Spanish Gold Coin. Will it be a fool's fake or worth mucho dinero? And later, the Old Man has a chance to buy a memorabilia collection from boxing superstar Muhammad Ali. Will he come out swinging for the KO or throw in the towel?