Complex sentence: Shi-Woon overhears on the radio that the Alliance claim that he has been captured, realising that this is a ploy to lure in the Goomoonryong he sets of to the KOA Building to meet up with his teacher.
Split into simpler sentences: Shi-Woon overhears on the radio that the Alliance claim that he has been captured. Realising that this is a ploy to lure in the Goomoonryong, he sets off to the KOA Building to meet up with his teacher.