Shocker and Jumbo are workmen on competing crews, both engaged in the dangerous work of excavating a network of tunnels between Brooklyn and Manhattan. Their rivalry, predicated on who will finish the tunnels first, only intensifies when they both begin fighting for the affections of journalist Pat Dodge. The two practically seem ready to kill each other for her -- but when Shocker is seriously injured by a tunnel collapse, and Jumbo saves his life, Shocker allows Jumbo to take over both crews and thereby win their contest.