Complex sentence: The Queen locates them and attempts to kill both of them, but together they best her, though in the battle, they accidentally mix the ship's store of baking powder with vinegar, causing a violent reaction that starts to sink the ship.
Split into simpler sentences: The Queen locates them and attempts to kill both of them, but together they best her. In the battle, they accidentally mix the ship's store of baking powder with vinegar, causing a violent reaction that starts to sink the ship.