Unexpected Power (データにゃないぜ!!悟空の超本気, Deta Nya Nai Ze!! Goku no Cho-honki) is the second episode of the Baby Saga and the eighteenth overall episode of Dragon Ball GT. The episode first aired on July 10, 1996. Its original American air date was November 28, 2003.
After the recap Sigma Force mocks Pan because they have knocked her unconscious, but they congratulate her on destroying Natt, who was the first ever Sigma Force member destroyed. Goku decides he has heard enough though, and he challenges the three of them to a battle. While Goku battles the Sigma Force, Trunks takes Pan to their Grand Tour spaceship to recuperate.
Goku seems to be outmatched at first because they have all of his moves downloaded in their memories, so General Rilldo prepares to make Giru, also known as T2006, the most decorated M-2 warrior in existence. Realizing that they can not kill Goku, the three machines warriors prepare him for Dr. Myuu, but Goku rebounds causing them to punch him in the stomach. Goku pretends to be hurt, but then he attacks them with energy blasts. Commander Nezi, Ribet, and Bizu escape into the walls, and then they begin playing jokes on Goku by lighting him on fire from behind and pulling his feet right out from under him. Goku wonders how they do this trick, but he decides it is not important enough to yet learn and destroys the building instead. Realizing they have lost their hiding place, the three robots decide to kill Goku instead of saving him for Dr. Myuu .
Meanwhile, Trunks arrives at the ship with Pan. The first thing he notices is that all their possessions have been thrown all over the ship. This causes him to head for the bag the Black Star Dragon Balls were in. He finds out that all 3 have been stolen, so he wakes up Pan, and the two prepare to get them back from Giru by force.
Elsewhere, the three robots combine into the Super Mega Cannon Sigma. This gives them additional strength, but Goku is not impressed. He uses their extendable arms as a ramp and gets a few good punches in before being blasted away. As Goku comes up from the rocks, he resumes fighting with new moves that the Sigma force has never seen. He then comments on how they have gotten stronger, but they have not gotten faster. This causes the robots to transform into the Super Sigma Aerial Attack mode. Goku acts like himself and matches their every move. He finally gets them to use the Killer Driller Attack, but then Goku triples his power.
General Rilldo realizes that Goku has been playing around the entire time, so he decides to head after Trunks and Pan to battle them. Meanwhile, Goku throws a few punches at the Sigma Force and destroys them with a Kamehameha. Just as Goku is about to head to the ship for food, he senses Rilldo heading towards the ship. He flies off on an intercept course. At the ship, Trunks and Pan also sense General Rilldo's humongous power, and they prepare to fight.