Henry Lorimer returns to the H & L Lumber Company camp, which he co-owns, with the good news that he has gotten a government contract which will reopen the camp. Adams, a friend of general manager Frank Barnes, agrees to underwrite the company so they can fill the order. As Lorimer signs on behalf of his deceased partner, John Hamilton, Adams expresses surprise that he plans to deforest Antler Valley, despite the fact that six logging companies have been driven out of the valley by squatters. Lorimer refuses to be driven out, however, and begins hiring his staff, including aggressive Hodge Mason, who asks to be the foreman, and immigrant Eric Smith as the cook. Logging work begins but is hampered by various accidents, including men being caught in animal traps and workers being shot at. Lorimer confronts the Cain family squatters, who swear their innocence because they know the loggers are working for the country's defense. When John Gordon shows up looking for work, he immediately flirts with Lorimer's daughter Perry, who rebuffs him as a "greenhorn." Lorimer hires John despite his inexperience, and one night, John is the first to see a forest fire raging outside the camp. Although the lumberjacks successfully extinguish the wide-ranging fire, Lorimer is killed by a falling tree. Perry continues running the company, despite Adams' offer to buy her out, and learns that the Cain family died in the fire. Frank offers to marry Perry, as he has always cared for her and now would like to help her, but she admits that she has never thought of him romantically. Perry puts John to work doing housework because he burned his hands while pulling her father out from under the tree. One day, a worker falls to his death when his safety rope is sabotaged, and Frank goes to the sheriff, while logger Olaf nails the bunkhouse door shut and he and other lumberjacks conduct their own investigation. Everyone suspects Eric because he is a foreigner, but they soon learn that he is a refugee and can be trusted. No new information is obtained from either the loggers or the sheriff and they return to work. They are again sabotaged by a dynamite explosion, which causes a landslide and blocks the train carrying the lumber to the sawmill. When John rides out to investigate the accident, a bullet narrowly misses hitting him, and explodes the dynamite supply. Frank orders a new supply of dynamite, then tells Perry that he suspects John of the sabotage. In a conversation with Olaf and Eric, John reveals his plan to lead everyone to believe that he can identify the saboteur. John later shows Frank and Perry a bullet that he claims will identify the saboteur, and stows the bullet in a knothole above his bunk for safekeeping. However, the bullet actually belongs to Olaf, who uses it as a match holder. That night, Olaf sees Mason steal the bullet from the knothole and arm himself before joining a card game with John. Olaf warns John by writing a message on a card, and John is prepared when Mason picks a fight. Frank breaks it up, and the next day, after Frank goes to clear the landslide, John privately tells Perry that he suspects Frank is in collusion with Mason, because he knew about the bullet. John now confesses that he is John Hamilton's son, and has inherited his father's share of the company on the provision that he begin as a lumberjack. John and Perry ride out to stop Frank from doing further damage, and while John struggles with Mason, who is setting new dynamite, Perry tries to force Frank to stop the train, but she is knocked unconscious. Frank sends the train ahead and Mason succeeds in blowing up the dynamite, but the lumber cars have already passed the point of explosion, and continue on to the lumber mill. John rescues Perry, and the sheriff arrests Mason and Frank.