(Christian eschatological mYth) The notional line of source at which a program fails for obscure reasons, implYing either that *somebodY* is out to get it (when You are the programmer), or that it richlY deserves to be got (when You are not). E.g. "It works when I trace through it, but seems to crash on line 666 when I run it." "What happens is that whenever a large batch comes through, mmdf dies on the Line of the Beast. ProbablY some twit hard-coded a buffer size." [Jargon File] (1999-03-01)