The description of General Zaroff’s smile foreshadows his violent and savage nature.
Foreshadowing is a hint by the author of what’s to come. Authors drop these little clues early on to build suspense and create a mood.
When Rainsford first meets General Zaroff, he does not know anything about him. Rainsford has published books on hunting, so Zaroff knows much more about him than he does about the general. The general is thrilled to find a skilled hunter in his clutches.
Although the description of the house is very grand and genteel, the description of the general hints at his dark side. The general introduces Ivan, the large mute brute, and Rainsford is definitely disturbed.
"He is a Cossack," said the general, and his smile showed red lips and pointed teeth. "So am I."
The red lips will make the reader think of blood, and the pointy teeth seem like an animal’s. This is ironic, because in the story Rainsford is the prey and Zaroff is the hunter. By this mere description, the reader begins to wonder if Zaroff is dangerous, and feel unsettled by him.
The use of foreshadowing in this story is not the only form of suspense. The classic predator and prey relationship is explored in different ways from beginning to end, starting with the conversation on the boat about whether or not animals can think.