And another one! Everyone's evil twin shows up. Their AU/mirror universe self. Whether they meet their evil twins or the evil twins just start replacing characters and pretending they're the original in an effort to take over the island. Or pod people start taking over. Hell, maybe only the people who are being replaced know when they're being replaced and we (and our characters) who haven't been replaced yet don't know what's entirely going on. MYSTERY. Controlled mystery, but mystery all the same.