Around 22 BBY, CT-19/39 was among the 20,000 Clone troopers led by General Nejaa Halcyon and Commander Anakin Skywalker during the Battle of Praesitlyn. He was among the best scouts in the Grand Army where he was able to penetrate deep into the enemy base and to memorize all the positions. He also recognized the weakness in their defense and went on his way back to pass on the knowledge.
When all the other scouts in his team were eliminated by battle droids, CT-19/39 was the only one who could convey the important message. On his way back, he was caught between a barrage of two fronts and was badly shot in the leg. Nevertheless, he continued his way crawling, but he lost a large amount of blood and died in a dry river bed.
- Jedi Trial (First appearance)