In the exposition of the short story "Three Skeleton Key" written by George G. Toudouze, the Narrator works on the island called Three Skeleton Key. The island got its name since three men a couple years ago tried escaping from Cayenne on a small, stolen canoe. Later they died of hunger and thirst. So, the Narrator works with two other men in a lighthouse by the names of Le Gleo and Itchoua. Late one night, the three men were working in the lighthouse, and they saw a ship sailing towards the island, but it wasn't stopping, it was headed straight towards the island. "Are they drunk, are they insane?" exclaimed Itchoua. Then they realize that there is no crew on board and no one is controlling the ship. Also, there are a bunch of rats on the ship that are huge. A couple hours later, the ship crashes in the reef by the island and sinks in the sea. They are relieved to see the rats gone, but then they start swimming back up to the surface and towards that island. The rats swim up to the shore of the island and the three men run into the lighthouse. The rats start climbing up the lighthouse and try biting through the walls. The three men are stuck inside the lighthouse for days.
The answer to your question is:
They make the play more dramatic (and)
They help reveal the setting.
<em>(I hope this helps!)</em>
