Complex sentence: Upon escaping the crumbling castle, Tir and company run into loyalist guards; in a selfless act of bravery, Viktor and Flik remain behind to fight the guards while Tir and everyone escapes.
Split into simpler sentences: Upon escaping the crumbling castle, Tir and company run into loyalist guards. In a selfless act of bravery, Viktor and Flik remain behind to fight the guards while Tir and everyone escapes.