The Forward is driven southward by relentless ice and runs low on coal, forcing the crew into an increasingly desperate situation. Despite looming mutiny, Hatteras insists on pushing further north. The brutal Arctic winter sets in, with the last lumps of coal burned by Christmas as temperatures plummet. They cross treacherous ice fields, bury fallen comrades, and leave markers to retrace their path. Eventually, they return to Forward, but not without great cost and emotional loss.