Kymn was planted by Black Sun as a sleeper agent in the spice mines of Kessel. Eventually, he became Second Administrator of the mining operations, under the Sullustan Chief Administrator Nien Nunb. As part of the crime syndicate's plot for galactic domination, Black Sun took over the spice mines during a revolt.
Following the revolt, the Black Sun leader Czethros himself arrived and attempted to transmit a coded signal that would activate the Black Sun cells that had been planted in countless key positions in the New Republic government. However, the transmitter was destroyed by Jedi apprentices Jaina Solo and Lowbacca before it could send its signal. The Jedi also freed the prisoners in the spice mines that had been imprisoned by the Black Sun mercenaries.
During the fighting, Kymn and his henchmen were lured into a deep section of the mines and then sealed behind heavy plasteel barricades, trapping them.