Despite their recent rise in prevalence, prequels are often a bad fit for television. Serialized TV is built for lengthy, evolving stories; stories that can grow from season to season; that can begin as one thing and end as something else entirely. Even episodic programs (your sitcoms, your procedurals) are bewitching for their innate boundlessness. They can go on forever, and knowing as much is comforting, intimate, and fun.