After having travelled west for weeks, the party of pioneers comes to a crossroads. It is time for their leader, George Donner, to make a choice. They face two diverging paths which lead to the same destination. One is well-documented – the other untested, but rumoured to be shorter. Donner’s decision will shape the lives of everyone travelling with him. The searing heat of the desert gives way to biting winds and a bitter cold that freezes the cattle where they stand. Driven to the brink of madness, the ill-fated group struggles to survive and minor disagreements turn into violent confrontations. Then the children begin to disappear. As the survivors turn against each other, a few begin to realise that the threat they face reaches beyond the fury of the natural elements, to something more primal and far more deadly.