Lak was one of the Empire's best scouts. He was a Shistavanen Wolfman and had no idea about the Rebellion until he one day stumbled upon a group of them on a rocky moon. Normally the Wolfmen were used to explore the Outer Rim Territories, so many of them lost touch with civilisation. After the destruction of the first Death Star, the Empire decided to stop all exploration of the Territories.
It was on the rocky moon that Sivrak started to question his beliefs in the Empire. The Rebels told him of the many atrocities the Emire had commited, and this changed Lak's affiliation forever. He became a Rebel, and promised not to reveal the whereabouts of the Rebels. His report said that no life was found on the moon, but when another scout found the Rebels, Lak knew he was in trouble. His deception was dscovered when one of the Rebels told the Empire everything while being tortured.
Sivrak fled, killing several stormtroopers that had been dispatched to find him. He found passage to Tatooine, and stayed in Mos Eisley.He wanted to make contact with the Alliance as a guide, for which he hoped to be paid a lot of credits. He had no way of reaching them, though, until he entered the Mos Eisley Cantina and met Dice Ibegon, a Florn Lamproid. She was a Rebel, and told Lak that she could help him. They quickly fell in love, but then Ben and Luke arrived, and when Ben had ignited his lightsaber and scared away Evazan and Ponda, Lak knew the authorities would be on their way. As the stormtroopers entered the cantina to inspect the disturbnce, Lak and Dice slipped out. They spent the night talking of the Reebllion and fell morein love with each other. Just a year before the Battle of Hoth, they joined the Alliance. But on Hoth, Dice was killed during the evacuation of Echo Base. She told Lak to continue the fight against the Empire, and to never stop believing in the Force.
During the Battle of Endor Lak piloted an X-Wing. When his ship was badly damaged, he died when he crashed on the moon of Endor. His consolation was several TIEs also crashed when they could not pull out in time.
He may have lost Dice on Hoth, and his life on Endor, but at last they were together again. In the Force.