Jek was one of the three clone troopers, alongside Clone Lieutenant Thire and Rys, who were dispatched to Rugosa as part of the escort accompanying Grand Master Yoda to secure an alliance between the Galactic Republic and King Katuunko of Toydaria. The group was ambushed by Separatist forces led by Asajj Ventress and, consequently, had to fight their way through her battle droid forces to reach the meeting point. In 19 BBY, Jek served under Clone Commander CC-1004 “Gree” at the Battle of Kashyyyk.