Complex sentence: Obi reasons with them, and so goes in the furnace and he tries to retrieve two of the antidotes from the furnace, but as he reaches a second antidote, it triggers a trap and it closes the door, lighting the furnace.
Split into simpler sentences: Obi reasons with them, and goes in the furnace to retrieve two of the antidotes. As he reaches for the second antidote, it triggers a trap and the door closes, lighting the furnace.