When the Empire killed thousands more in a brutal and clumsy attempt to suppress growing anti-Imperial feeling, the radicals organizing the uprising recruited Helkosh to infiltrate the Imperial Academy. The true nature of his mission was revealed only on the last few weeks there - he would be a suicide bomber and destroy the Admiral who had ordered the initial bombardment, as well as cause as much death as he could with the explosive vest he was given. However, another bomber got close to Admiral Sabbani, and a visiting Moff, first. Helkosh was apprehended fleeing the carnage - the Moff was killed and Sabbani critically wounded - and sent to Olchark Prison in the Outer Rim.
There, he was slated for execution after interrogation revealed he had no useful information about the Kelshamiri rebels. Everything he knew was now years out of date. For an unknown reason, Helkosh was again spared, although free on the surface of the harsh planet, he would not have survived long if not for an Alliance raid on the prison facility that gave him an escape. Near-dead from exposure, he was treated aboard the Alliance medical ship Mercy, then volunteered to join the infantry.
After basic training he was assigned to Squad 16782. Some questioned this posting due to his clear piloting talent, but the Navy could not risk a fanatic suicide bomber at the controls of a X-Wing or Y-Wing. Let him, said one privately, blow himself up with a hundred-credit grenade. It'll be cheaper.