Task: Question Generation
Input (English): Context : For decades only Episode 3 of The Enemy of the World was known to have survived erasure, but the five missing episodes were announced as recovered by the BBC on 11 October 2013 along with four of the missing episodes of the following serial, The Web of Fear. 
Subject : The Enemy of the World 
Relation : series
Output (English): To which series does The Enemy of the World belong?