Rainsford (the protagonist from Connell's short story "The Most Dangerous Game") first realizes that he will be Zaroff's next prey soon after learning about the "game" Zaroff has created.
Rainsford, curious about the new prey, begins to question what animal can possibly be the most dangerous prey. After finding out that man is Zaroff's new prey, Zaroff asks Rainsford if he would like to see his collection of heads. Rainsford politely declines saying that he is tired. Zaroff tells him that he is sure that he could use the rest and needs to be ready the following day to join him on a new hunt with a rather "rather promising prospect." Unbeknownst to him, Rainsford is the prospect.
Rainsford then tells Zaroff that he wishes to leave the island--that night. Zaroff continues to tell Rainsford that they must hunt together. Instead of them hunting on the same side though (as Rainsford believes), Zaroff will hunt Rainsford.
"My dear fellow," said the general, "have I not told you I always mean what I say about hunting? This is really an inspiration. I drink to a foeman worthy of my steel--at last." The general raised his glass, but Rainsford sat staring at him.
"You'll find this game worth playing," the general said enthusiastically." Your brain against mine. Your woodcraft against mine. Your strength and stamina against mine. Outdoor chess! And the stake is not without value, eh?"
Therefore, after refusing Zaroff's request to join him on a hunt, Rainsford finds out that he will, instead, be the prey. Zaroff retires shortly thereafter and Rainsford is left to change into the clothes, provided by Ivan, and head for the bush.