Thought to have been killed in the Shaolin Tournament, Sub-Zero mysteriously returns. It is believed he travelled into the Outworld to again attempt to assassinate Shang Tsung. To do so he must fight his way through Shao Kahn's tournament.
When Sub-Zero failed to return from the Shaolin tournament and rumor of Shang Tsung's survival reached the Lin Kuei clan, they immediately sent another assassin to complete the task. This new warrior is actually the younger brother of the original Sub-Zero.
He enters the outworld contest and accomplishes his task. He learns of Scorpion's foul vendetta against his brother but will never know why his life was spared. Perhaps a third tournament is in his future?