Nightwolf informs Liu Kang about the invading Cybers -a group of robots from the Outworld who are led by Sektor and Cyrax. During the battle, Kitana reunites with Liu. The group fight against the Cybers, but then have to take cover due to the Cyber's unrelenting fire. However several of the Cybers are suddenly frozen up, as Sub-Zero arrives.

This Sub-Zero is the brother of the one Liu had killed in Mortal Kombat, and had helped the group in the past before suddenly disappearing. He explains that he sought seclusion and inner peace, but is now back with a warning: Scorpion is planning to invade the Earth Realm. Sonya is against trusting Sub-Zero, but he claims that Outworlders tried to recruit him to join Scorpion's cause. Rayden then appears, and is about to inform them of Scorpion's plan until Jax explains Sub-Zero has already told them.

The Defenders of the Realm head back to their headquarters via the dragon jets. Stryker is reluctant to let Sub-Zero come along, but relents. At the base, Sub-Zero meets Nightwolf, who is the team's tech guy and is able to find where the dimensional rips are. These rips are what are letting Outworlders to invade the Earth. An alarm then goes off, but it's not a rip -they're under attack! It's a group of Nomad, led by Karbrac. Everyone believes Sub-Zero has betrayed them, but he says he knew nothing about it. Most of the team head out to fight, but Rayden insists Sub-Zero remains here with Nightwolf. He then teleports away, to prepare a portal to get rid of the Nomad.

Nightwolf combines with his wolf, Kiva, to power himself up. Karbrac and some other Nomad invade the base, but Nightwolf and Sub-Zero fight them off. Sub-Zero is challenged by Karbrac in a one on one battle, and he quickly defeats his opponent. Rayden then reappears and teleports the Nomad away to a realm that they can't return from. The rest of the team see off the Nomad outside, and come back in. Nightwolf explains that Sub-Zero helped them, and Rayden then finds a tracking device had been planted on Sub-Zero, which is how the Nomad found out where they were. Sub-Zero realizes that when the Nomad tried to recruit him, they must have tagged him with it then.

Sonya tells Sub-Zero that she's sorry for giving him a hard time, it's just difficult for her to trust others. She can't stand to see people she cares about getting hurt, especially after the deaths of his two previous partners. Nightwolf then says they've got a big time Kombat alert, and Sub-Zero says it's Scorpion. Rayden says that Mortal Kombat continues...

Notes

-SCRIPT DIFFERENCES: Click here for details.

-Originally, the first two episodes of the show were meant to be one episode, as per the script available in the writer's guide. As mentioned in the script differences, the plot was altered to split the story into two episodes, with some new scenes added. The Nomad battle and the tracking device on Sub-Zero weren't in the original script.

-When Liu first sees Kitana, he seems surprised. It almost looks as if a scene was cut here or something.

-This cartoon is a sequel to the first live action movie, and from what's said in this episode, a few years have passed. The show's biggest omission is Johnny Cage, who was a main character in the movie, but is never mentioned here.

-Sektor is not seen retreating with Cyrax and the other Cybers. He apparently got away by himself, since he'll show up again in the series.

-The flashback showing the fight between Liu and the original Sub-Zero has a slightly different outcome. In this episode, Sub-Zero gets frozen solid whilst standing. In the movie, the water Liu throws at him becomes an icicle, which stabs through Sub-Zero and pins him to a wall. He then gets frozen.

-Also, Liu Kang is wearing a vest during the flashback, making him look like his Mortal Kombat 4 counterpart. This episode was aired around a year before that game out though.

-The Nomad and their leader, Karbrac, are based on Baraka, a character who appeared in Mortal Kombat II.

-I haven't found a reason as to why they didn't just call Karbrac Baraka in this episode though. Nightwolf explains that Karbrac is the "new" Nomad leader, which suggests Baraka is dead or something.

-In the games, the Nomad are called the Tarkatan. However this fact didn't come into place until well after this cartoon was produced.

-In the early days of the games, Raiden's name was spelt "Rayden" in the console ports, due to an issue with the Raiden shooting games. This change also effects the series, as seen in the credits.

Errors

-When Liu first contacts Nightwolf, his bandana disappears as he moves back.
-The Sektor Nightwolf displays on his computer is just a Cyber recolored red. The actual Sektor has a different design.
-The projectiles Jax throws out are colored yellow, but the blast that hits the Cyber is colored blue.
-Jax is also seen throwing out two projectiles, but only one is seen when the Cybers get hit.
-An explosion effect slightly overlaps Sonya's head during this shot.
-When the Cybers all start firing, one energy blast can be seen passing straight through the crotch of the middle Cyber a few times.
-This shot shows four Cybers running towards a portal, but when the shot changes, one of the Cybers is gone, and replaced with Cyrax.
-Also during the above, when the Defenders are shown running after the Cybers, Sonya's hair is colored black instead of yellow.
-When Sonya does her kiss of death fatality, the energy sphere is initially colored yellow. Then it switches to pink. Then when she throws it out, it's back to yellow/orange again.
-During this shot, the back of Sub-Zero's shirt is colored white instead of black.
-Nightwolf's chair is transparent during this shot.
-When the Nomad jets are first seen firing on the mountain, a smoke effect briefly overlaps them.
-During this shot, the back of Sub-Zero's shirt is skin colored instead of black.
-The same error happens again when Sub-Zero starts to follow the rest of the team.
-During this shot, some kind of mark appears and stays present for the duration of the shot.
-During this shot, Stryker and Kitana's mouths start opening and closing, but they don't actually say anything. Jax's mouth then also starts to open and close, but again, no words come out. After Liu finishes bowing his mouth also open and closes briefly, but he says nothing.