That's a hard question to answer, as to how i get my ideas. Honestly, sometimes they just come to me or I draw ideas from a certain event that happens around me. As for this idea, I've always wanted to figure out what would actually happen if a random person you accepted turned out to be a serial killer and what would happen. It was an intriguing premise because it could happen in real life. Also thank you, I'm glad to have fans like you, tell your friends about it :)