Complex sentence: Prior to their escape, Addison and Gabe discover and retrieve samples the rare plants found on Kreisler and Freeman before being ambushed by several rebel forces led by Red Section lieutenant White Scorpion.
Split into simpler sentences: Prior to their escape, Addison and Gabe discover more of the rare plants found on Kreisler and Freeman. Upon retrieving samples of the plants, they are ambushed by several rebel forces led by Red Section lieutenant White Scorpion.