Complex sentence: Opal splits apart as Pearl and Amethyst squabble about forgetting the purpose of their mission, but Steven shows the others that he managed to acquire the beetle, which Garnet puts away in a terrarium for safekeeping.
Split into simpler sentences: Opal splits apart as Pearl and Amethyst squabble about forgetting the purpose of their mission. However, Steven shows the others that he managed to acquire the beetle, which Garnet puts away in a terrarium for safekeeping.