Kiritsugu Emiya has placed Shirou Emiya in charge of saving humanity after succumbing to an unpleasant fate. The planet is dying, and time is running out, but will Shirou have the will to fulfill this responsibility if the redemption he seeks comes at the expense of his last remaining family member, his younger sister? Shirou is now forced to choose between remaining a hero of justice and becoming the exact evil his ideal has pledged to defeat. The orphan is once again alone, but his body is still formed of blades. With his oath under snow, the Fifth Holy Grail War has begun.